Title: Electric motor control device
Abstract: Host control section 8 is provided with simulation model 8c for simulating the signal transmission characteristics of an electric motor control device. Host control section 8 performs an operation on the actual position command signal .theta.ref that is supplied from the host device in accordance with the simulation model, calculates the speed and position of the electric motor corresponding to the actual position command signal .theta.ref, and applies this speed and position as first simulation speed signal .omega.F and first simulation position signal .theta.F, respectively, with each second control sampling period t2. Host control section 8 further generates a linear combination of .theta.ref-.theta.F and .omega.F using, as combination coefficients, constants determined by parameters that characterize the simulation model, and supplies this linear combination as feedforward torque signal TFF for each second control sampling period t2. In this way, the occurrence of error between the actual position signal and the simulation position signal can be prevented even when the control sampling period of the feedforward operation differs from the control sample cycle of the feedback operation.
Patent Number: 6,873,132 Issued on 03/29/2005 to Kaku, et al.
| Inventors:
|
Kaku; Souki (Fukuoka, JP);
Honda; Hideki (Fukuoka, JP);
Oguro; Ryuichi (Fukuoka, JP);
Miyagawa; Hidekazu (Fukuoka, JP)
|
| Assignee:
|
Kabushiki Kaisha Yaskawa Denki (Fukuoka, JP)
|
| Appl. No.:
|
343955 |
| Filed:
|
February 4, 2003 |
| PCT Filed:
|
August 3, 2001
|
| PCT NO:
|
PCT/JP01/06682
|
| 371 Date:
|
February 4, 2003
|
| 102(e) Date:
|
February 4, 2003
|
| PCT PUB.NO.:
|
WO02/13368 |
| PCT PUB. Date:
|
February 14, 2002 |
Foreign Application Priority Data
| Aug 08, 2000[JP] | 2000-239786 |
| Current U.S. Class: |
318/798; 318/632; 318/805 |
| Intern'l Class: |
H02P 005//28 |
| Field of Search: |
318/798-804,632,805
|
References Cited [Referenced By]
U.S. Patent Documents
| 4338559 | Jul., 1982 | Blaschke et al. | 318/805.
|
| 5461293 | Oct., 1995 | Rozman et al. | 318/603.
|
| 5532571 | Jul., 1996 | Masaki et al. | 318/809.
|
| 5729113 | Mar., 1998 | Jansen et al. | 318/799.
|
| 5874821 | Feb., 1999 | Monleone.
| |
| 5919114 | Jul., 1999 | Kamada et al. | 477/159.
|
| 6008618 | Dec., 1999 | Bose et al.
| |
| Foreign Patent Documents |
| 05-236777 | Sep., 1993 | JP.
| |
| 10-337070 | Dec., 1998 | JP.
| |
| 2000-092881 | Mar., 2000 | JP.
| |
Primary Examiner: Duda; Rina
Attorney, Agent or Firm: Knobbe Martens Olson & Bear, LLP
Parent Case Text
This application is the U.S. National Phase under 35 U.S.C. .sctn.371 of
International Application PCT/JP01/06682, filed Aug. 3, 2001, which claims
priority to Japanese Patent Application No. 2000-239786, filed Aug. 8,
2000. The International Application was published under PCT Article 21(2)
in a language other than English.
Claims
What is claimed is:
1. An electric motor control device for providing appropriate torque
commands to a machine system that comprises: a load machine, a transfer
mechanism for transferring power, an electric motor for driving said load
machine by way of said transfer mechanism, and a power conversion circuit
for providing electric power for driving said electric motor based on said
torque commands; said torque commands being provided to said power
conversion circuit such that said machine system performs desired
movements; and said electric motor control device comprising:
a command generator for providing an actual command signal;
an actual state observer for observing the state quantities of said machine
system and providing an actual response signal with each first control
sampling time period;
a host control section for providing a first simulation position signal, a
first simulation speed signal, and a first simulation torque signal with
each second control sampling time period that is longer than said first
control sampling time period based on said actual command signal;
a regulatory control section for providing a second simulation torque
signal with each first control sampling time period based on said first
simulation position signal, said first simulation speed signal, and said
actual response signal;
a torque compensator for providing a third simulation torque signal with
each second control sampling time period based on said first simulation
position signal, said first simulation speed signal, and said actual
response signal; and
a torque synthesizer for providing torque commands with each first control
sampling time period based on said first simulation torque signal, said
second simulation torque signal, and said third simulation torque signal.
2. An electric motor control device according to claim 1, wherein said
first torque compensator comprises:
a subtracter for providing a J1 simulation signal based on said actual
response signal and said first simulation position signal;
a first coefficient multiplier for providing a J2 simulation signal based
on said J1 simulation signal;
a differentiator for providing a J3 simulation signal with each second
control sampling time period based on said actual response signal;
an adder/subtracter for providing a J4 simulation signal based on said J2
simulation signal, said J3 simulation signal, and said first simulation
speed signal;
a second coefficient multiplier for providing a J5 simulation signal based
on said J4 simulation signal; and
a discrete integrator for providing said third simulation torque signal
with each second control sampling time period based on said J5 simulation
signal.
3. An electric motor control device according to claim 1, provided with
means for configuring said host control section, said torque compensator,
said regulatory control section, and said torque synthesizer by a
plurality of processors.
4. An electric motor control device for providing appropriate torque
commands to a machine system that comprises: a load machine, a transfer
mechanism for transferring power, an electric motor for driving said load
machine by way of said transfer mechanism, and a power conversion circuit
for providing electric power for driving said electric motor based on said
torque commands; said torque commands being provided to said power
conversion circuit such that said machine system performs desired
movements; and said electric motor control device comprising:
a command generator for providing an actual command signal;
an actual state observer for observing the state quantities of said machine
system and providing an actual response signal with each first control
sampling time period;
a host control section for providing a first simulation position signal, a
first simulation speed signal, and a first simulation torque signal with
each second control sampling time period that is longer than said first
control sampling time period based on said actual command signal;
a regulatory control section for providing a second simulation torque
signal with each first control sampling time period based on said first
simulation position signal, said first simulation speed signal, and said
actual response signal;
a torque compensator for providing a third simulation torque signal with
each second control sampling time period based on said second simulation
positional signal; and
a torque synthesizer for providing torque commands with each first control
sampling time period based on said first simulation torque signal, said
second simulation torque signal, and said third simulation torque signal.
5. An electric motor control device according to claim 4, provided with
means for configuring said host control section, said torque compensator,
said regulatory control section, and said torque synthesizer by a
plurality of processors.
6. An electric motor control device according to claim 1 or 4, wherein said
regulatory control section comprises:
a subtracter for providing a D1 simulation signal based on said first
simulation position signal and said actual response signal;
a first coefficient multiplier for providing a D2 simulation signal based
on said D1 simulation signal;
a differentiator for providing a D3 simulation signal with each first
control sampling time period based on said actual response signal;
an adder/subtracter for providing a D4 simulation signal based on said D2
simulation signal, said D3 simulation signal, and said first simulation
speed signal; and
a second coefficient multiplier for providing said second simulation torque
signal based on said D4 simulation signal.
7. An electric motor control device according to claim 1 or 4, wherein said
regulatory control section comprises:
a first command compensator for providing an F1 simulation signal with each
first control sampling time period based on said first simulation position
signal;
a second command compensator for providing an F2 simulation signal with
each first control sampling time period based on said first simulation
speed signal;
a subtracter for providing an F3 simulation signal based on said F1
simulation signal and said actual response signal;
a first coefficient multiplier for providing an F4 simulation signal based
on said F3 simulation signal;
a differentiator for providing an F5 simulation signal in said first
control sampling time period based on said actual response signal;
an adder/subtracter for providing an F6 simulation signal based on said F4
simulation signal, said F5 simulation signal, and said F2 simulation
signal; and
a second coefficient multiplier for providing said second simulation torque
signal based on said F6 simulation signal.
8. An electric motor control device for providing appropriate torque
commands to a machine system that comprises: a load machine, a transfer
mechanism for transferring power, an electric motor for driving said load
machine by way of said transfer mechanism, and a power conversion circuit
for providing electric power for driving said electric motor based on said
torque commands; said torque commands being provided to said power
conversion circuit such that said machine system performs desired
movements; and said electric motor control device comprising:
a command generator for providing an actual command signal;
an actual state observer for observing the state quantities of said machine
system and providing an actual response signal with each first control
sampling time period;
a host control section for providing a first simulation position signal, a
first simulation speed signal, and a first simulation torque signal with
each second control sampling time period that is longer than said first
control sampling time period based on said actual command signal;
a simulation observer for providing an estimated position signal and an
estimated speed signal with each first control sampling time period based
on a torque command and said actual response signal;
a regulatory control section for providing a second simulation torque
signal with each first control sampling time period based on said first
simulation position signal, said first simulation speed signal, said
estimated position signal, and said estimated speed signal;
a torque compensator for providing a third simulation torque signal with
each second control sampling time period based on said second simulation
torque signal; and
a torque synthesizer for providing a torque command with each first control
sampling time period based on said first simulation torque signal, said
second simulation torque signal, and said third simulation torque signal.
9. An electric motor control device according to claim 8, wherein said
regulatory control section comprises:
a subtracter for providing an E1 simulation signal based on said first
simulation position signal and said estimated position signal;
a first coefficient multiplier for providing an E2 simulation signal based
on said E1 simulation signal;
an adder/subtracter for providing an E3 simulation signal based on said E2
simulation signal, said first simulation speed signal, and said estimated
speed signal; and
a second coefficient multiplier for providing said second simulation torque
signal based on said E3 simulation signal.
10. An electric motor control device according to claim 8, wherein said
regulatory control section comprises:
a first command compensator for providing a G1 simulation signal with each
first control sampling time period based on said first simulation position
signal;
a second command compensator for providing a G2 simulation signal with each
first control sampling time period based on said first simulation speed
signal;
a subtracter for providing a G3 simulation signal based on said G1
simulation signal and said estimated position signal;
a first coefficient multiplier for providing a G4 simulation signal based
on said G3 simulation signal;
an adder/subtracter for providing a G5 simulation signal based on said G4
simulation signal, said estimated speed signal, and said G2 simulation
signal; and
a second coefficient multiplier for providing said second simulation torque
signal based on said G5 simulation signal.
11. An electric motor control device according to claim 8, provided with
means for configuring said host control section, said torque compensator,
said simulation observer, said regulatory control section and said torque
synthesizer by a plurality of processors.
12. An electric motor control device according to any one of claims 1
through 8, wherein said host control section comprises:
a simulation signal processor for providing said first simulation position
signal and said first simulation speed signal;
a host controller for providing said first simulation torque signal based
on said actual command signal, said first simulation position signal from
said simulation signal processor, and said first simulation speed signal
from said simulation signal processor;
a simulation regulatory controller for providing a fourth simulation signal
based on said first simulation position signal from said simulation signal
processor and said first simulation speed signal from said simulation
signal processor;
a first adder for providing a first simulation signal based on said first
simulation torque signal and said fourth simulation; and
a simulation model for providing a second simulation signal and a third
simulation signal based on said first simulation signal,
wherein said first simulation position signal and said first simulation
speed signal provided by said simulation signal processor are created with
each second control sampling time period based on said second simulation
signal and said third simulation signal.
13. An electric motor control device according to claim 12, wherein said
simulation model comprises:
a first subtracter for providing an A1 simulation signal based on said
first simulation signal and said second simulation signal;
a first coefficient multiplier for providing an A2 simulation signal based
on said A1 simulation signal;
a second subtracter for providing an A3 simulation signal based on said A2
simulation signal and said third simulation signal;
a second coefficient multiplier for providing an A4 simulation signal based
on said A3 simulation signal;
a third coefficient multiplier for providing an A5 simulation signal based
on said A4 simulation signal;
a first integrator for providing said third simulation signal based on said
A5 simulation signal; and
a second integrator for providing said second simulation signal based on
said third simulation signal.
14. An electric motor control device according to claim 12, wherein said
simulation regulatory controller comprises:
a first coefficient multiplier for providing a B1 simulation signal based
on said first simulation position signal;
a second adder for providing a B2 simulation signal based on said B1
simulation signal and said first simulation speed signal; and
a second coefficient multiplier for providing said fourth simulation signal
based on said B2 simulation signal.
15. An electric motor control device according to claim 12, wherein said
host controller comprises:
a first subtracter for providing a C1 simulation signal based on said
actual command signal and said first simulation position signal;
a first coefficient multiplier for providing a C2 simulation signal based
on said C1 simulation signal;
a second subtracter for providing a C3 simulation signal based on said
first simulation speed signal and said C2 simulation signal; and
a second coefficient multiplier for providing said first simulation torque
signal based on C3 simulation signal.
16. An electric motor control device according to any one of claims 1
through 8, wherein said torque synthesizer comprises:
a command filter for providing an H1 simulation signal based on said second
simulation torque signal; and
an adder for providing a torque command based on said H1 simulation signal,
said first simulation torque signal, and said third simulation torque
signal.
17. An electric motor control device according to any one of claim 1
through 8, wherein said torque synthesizer comprises:
a command filter for providing an I1 simulation signal based on said second
simulation torque signal;
a command compensator for providing an I2 simulation signal with each first
control sampling time period based on said first simulation torque signal;
and
an adder for providing a torque command based on said I1 simulation signal,
said third simulation torque signal, and said I2 simulation signal.
18. An electric motor control device according to claim 4 or 8, wherein
said torque compensator comprises:
a discrete integrator for providing said third simulation torque signal
with each second control sampling time period based on said second
simulation torque signal.
Description
TECHNICAL FIELD
The present invention relates to a control device of an electric motor
(such as a dc electric motor, an induction electric motor, a synchronous
electric motor, or a linear motor) that drives a load machine such as a
table or robot arm in machine tool.
BACKGROUND ART
The manufacturing industry is now widely employing two-degrees-of-freedom
control devices having a feedback control system that provides second
simulation torque signals and torque commands to, and a feedforward
control system that provides first simulation torque signals to a machine
system that comprises: a load machine such as a table or robot arm in a
machine tool; a drive device such as a dc electric motor, an induction
electric motor, a synchronous electric motor, an electromagnet, or a
linear motor that drives the load machine; and a transmission mechanism
that links the load machine and the drive device.
Examples of such devices are described in Japanese Patent Laid-Open No.
119402/1992 and Japanese Patent Laid-Open No. 138223/1992. FIG. 1 is a
block diagram showing an example of a two-degrees-of-freedom control
device of the prior art.
As shown in FIG. 1, the position control device of the prior art is
provided with: motor 3, feedforward signal operational circuit 21,
rotation detector 20, position control circuit 22, speed control circuit
23, and control means (torque control circuit) 24. Electric motor 3 drives
load machine 1 by way of torque transfer mechanism 2. Feedforward signal
operational circuit 21 receives rotation angle command signals of the
electric motor .theta..sub.ms from command generator 7 and, by means of a
prescribed functional operation that includes at least two integrating
operations, provides a simulation rotation angle signal .theta..sub.o, a
simulation speed signal .omega..sub.o, and a first simulation torque
signal T.sub.o as output. Rotation detector 20 detects the rotational
speed and rotation angle of the electric motor. Position control circuit
22 supplies a first speed signal based on the simulation rotation angle
signal .theta..sub.o and the actual rotation angle signal .theta..sub.m
provided from the rotation detector 20. Speed control circuit 23 provides
as output a second simulation torque signal T.sub.1 based on the
simulation speed signal .omega..sub.o, the first speed signal, and the
actual speed signal .omega..sub.m provided from the rotation detector 20.
Control means 24 controls the torque of the electric motor 3 based on the
first simulation torque signal T.sub.0 and the second simulation torque
signal T.sub.1. This circuit configuration allows high-response position
control performance.
When the control sampling time period of the feedforward operation becomes
greater than the control sampling time period of the feedback operation,
however, the difference in the sampling times causes a discrete modeling
error even though the numerical model of the feedforward may match the
object of control. As a result, deviation occurs between the actual
rotation angle signal and the simulation rotation angle signal, and
overshoot or vibration may therefore occur in the actual rotation angle
signal.
It is an object of the present invention to provide an electric motor
control device capable of realizing superior control performance in which
deviation does not occur between the actual rotation angle signal and the
simulation rotation angle signal even when the control sampling time
period of the feedforward operation differs from the control sampling time
period of the feedback operation.
DISCLOSURE OF THE INVENTION
To solve the above-described problems, a first embodiment of the invention
is provided with the following means:
a command generator for providing actual command signals;
an actual state observer for observing the state quantities of the machine
system and the power conversion circuit and providing an actual response
signal with each first control sampling time period;
a host control section for providing a first simulation position signal, a
first simulation speed signal, and a first simulation torque signal with
each second control sampling time period that is longer than the first
control sampling time period based on the actual command signals;
a regulatory control section for providing a second simulation torque
signal with each first control sampling time period based on the first
simulation position signal, the first simulation speed signal, and the
actual response signal;
a torque compensator for providing a third simulation torque signal with
each second control sampling time period based on the first simulation
position signal, the first simulation speed signal, and the actual
response signal; and
a torque synthesizer for providing torque commands with each first control
sampling time period based on the first simulation torque signal, the
second simulation torque signal, and the third simulation torque signal.
A second embodiment of the invention is provided with the following means:
a command generator for providing actual command signals;
an actual state observer for observing the state quantities of the machine
system and the power conversion circuit and providing an actual response
signal with each first control sampling time period;
a host control section for providing a first simulation position signal, a
first simulation speed signal, and a first simulation torque signal based
on the actual command signal with each second control sampling time period
that is longer than the first control sampling time period;
a regulatory control section for providing second simulation torque signal
with each first control sampling time period based on the first simulation
position signal, the first simulation speed signal, and the actual
response signal;
a torque compensator for providing a third simulation torque signal with
each second control sampling time period based on the second simulation
torque signal; and
a torque synthesizer for providing torque commands with each first control
sampling time period based on the first simulation torque signal, the
second simulation torque signal and the third simulation torque signal.
A third embodiment of the invention is provided with the following means:
a command generator for providing an actual command signal;
an actual state observer for observing the state quantities of the machine
system and the power conversion circuit and providing an actual response
signal with each first control sampling time period;
a host control section for providing a first simulation position signal, a
first simulation speed signal, and a first simulation torque signal with
each second control sampling time period that is longer than the first
control sampling time period based on the actual command signal;
a simulation observer for providing an estimated position signal and an
estimated speed signal with each first control sampling time period based
on a torque command and the actual response signal;
a regulatory control section for providing a second simulation torque
signal with each first control sampling time period based on the first
simulation position signal, the first simulation speed signal, the
estimated position signal, and the estimated speed signal;
a torque compensator for providing a third simulation torque signal with
each second control sampling time period based on the second simulation
torque signal; and
a torque synthesizer for providing a torque command with each first control
sampling time period based on the first simulation torque signal, the
second simulation torque signal and the third simulation torque signal.
A fourth embodiment of the invention is provided with the following means:
a simulation signal processor for providing a first simulation position
signal and a first simulation speed signal;
a host controller for providing a first simulation torque signal based on
an actual command signal the first simulation position signal from the
simulation signal processor, and the first simulation speed signal from
the simulation signal processor;
a simulation regulatory controller for providing a fourth simulation signal
based on the first simulation position signal .theta.F from the simulation
signal processor and the first simulation speed signal .omega.F from the
simulation signal processor;
an adder for providing a first simulation signal based on the first
simulation torque signal and the fourth simulation signal; and
a simulation model for providing a second simulation signal and a third
simulation signal based on the first simulation signal,
wherein the first simulation position signal and the first simulation speed
signal provided by the simulation signal processor are created with each
second control sampling time period based on the second simulation signal
and the third simulation signal.
A fifth embodiment of the invention is provided with the following means:
a coefficient multiplier for providing an A1 simulation signal based on an
A2 simulation signal;
a first integrator for providing the third simulation signal based on the
A1 simulation signal;
a second integrator for providing the second simulation signal based on the
third simulation signal;
a first subtracter for providing an A3 simulation signal based on the first
simulation signal and the second simulation signal;
a first coefficient multiplier for providing an A4 simulation signal based
on the A3 simulation signal;
a second subtracter for providing an A5 simulation signal based on the A4
simulation signal and the third simulation signal; and
a second coefficient multiplier for providing the A2 simulation signal
based on the A5 simulation signal.
A sixth embodiment of the invention is provided with the following means:
a first coefficient multiplier for providing a B1 simulation signal based
on the second simulation signal;
an adder for providing a B2 simulation signal based on the B1 simulation
signal and the third simulation signal; and
a second coefficient multiplier for providing the fourth simulation signal
based on the B2 simulation signal.
A seventh embodiment of the invention is provided with the following means:
a first subtracter for providing a C1 simulation signal based on the actual
command signal and the first simulation position signal;
a first coefficient multiplier for providing a C2 simulation signal based
on the C1 simulation signal;
a second subtracter for providing a C3 simulation signal based on the first
simulation speed signal and the C2 simulation signal; and
a second coefficient multiplier for providing the first simulation torque
signal based on the C3 simulation signal.
An eighth embodiment of the invention is provided with the following means:
a subtracter for providing a D1 simulation signal based on the first
simulation position signal and the actual response signal;
a first coefficient multiplier for providing a D2 simulation signal based
on the D1 simulation signal;
a differentiator for providing a D3 simulation signal with each first
control sampling time period based on the actual response signal;
an adder/subtracter for providing a D4 simulation signal based on the D2
simulation signal and the D3 simulation signal; and
a second coefficient multiplier for providing a second simulation torque
signal based on the D4 simulation signal.
A ninth embodiment of the invention is provided with the following means:
a subtracter for providing an E1 simulation signal based on the first
simulation position signal and the estimated position signal;
a first coefficient multiplier for providing an E2 simulation signal based
on the E1 simulation signal;
an adder/subtracter for providing an E3 simulation signal based on the E2
simulation signal, the first simulation speed signal, and the estimated
speed signal; and
a second coefficient multiplier for providing a second simulation torque
signal based on the E3 simulation signal.
A tenth embodiment of the invention is provided with the following means:
a first command compensator for providing an F1 simulation signal with each
first control sampling time period based on the first simulation position
signal;
a second command compensator for providing an F2 simulation signal with
each first control sampling time period based on the first simulation
speed signal;
a subtracter for providing an F3 simulation signal based on the F1
simulation signal and the actual response signal;
a first coefficient multiplier for providing an F4 simulation signal based
on the F3 simulation signal;
a differentiator for providing an F5 simulation signal with each first
control sampling time period based on the actual response signal;
an adder/subtracter for providing an F6 simulation signal based on the F4
simulation signal, the F5 simulation signal, and the F2 simulation signal;
and
a second coefficient multiplier for providing the second simulation torque
signal based on the F6 simulation signal.
An eleventh embodiment of the invention is provided with the following
means:
a first command compensator for providing a G1 simulation signal with each
first control sampling time period based on the first simulation position
signal;
a second command compensator for providing a G2 simulation signal with each
first control sampling time period based on the first simulation speed
signal;
a subtracter for providing a G3 simulation signal based on the G1
simulation signal and the estimated position signal;
a first coefficient multiplier for providing a G4 simulation signal based
on the G3 simulation signal;
an adder/subtracter for providing a G5 simulation signal based on the G4
simulation signal, the estimated speed signal, and the G2 simulation
signal; and
a second coefficient multiplier for providing a second simulation torque
signal based on the G5 simulation signal.
A twelfth embodiment of the invention is provided with the following means:
a command filter for providing an H1 simulation signal based on the second
simulation torque signal; and
an adder for providing a torque command based on the H1 simulation signal,
the first simulation torque signal, and the third simulation torque
signal.
A thirteenth embodiment of the invention is provided with the following
means:
a command filter for providing an I1 simulation signal based on the second
simulation torque signal;
a command compensator for providing an I2 simulation signal with each first
control sampling time period based on the first simulation torque signal;
and
an adder for providing a torque command based on the I1 simulation signal,
the third simulation torque signal, and the I2 simulation signal.
A fourteenth embodiment of the invention is provided with the following
means:
a subtracter for providing a J1 simulation signal based on the actual
response signal and the first simulation position signal;
a first coefficient multiplier for providing a J2 simulation signal based
on the J1 simulation signal;
a differentiator for providing a J3 simulation signal with each second
control sampling time period based on the actual response signal;
an adder/subtracter for providing a J4 simulation signal based on the J2
simulation signal, the J3 simulation signal, and the first simulation
speed signal;
a second coefficient multiplier for providing a J5 simulation signal based
on the J4 simulation signal; and
a discrete integrator for providing a third simulation torque signal with
each second control sampling time period based on the J5 simulation
signal.
A fifteenth embodiment of the invention is provided with a discrete
integrator for providing a third simulation torque signal with each second
control sampling time period based on the second simulation torque signal.
A sixteenth embodiment of the invention is provided with means for
configuring the host control section, the torque compensator of the first
embodiment, the regulatory control section, and the torque synthesizer by
a plurality of processors.
A seventh embodiment of the invention is provided with means for
configuring the host control section, the torque compensator of the second
embodiment, the regulatory control section, and the torque synthesizer by
a plurality of processors.
An eighteenth embodiment of the invention is provided with means for
configuring the host control section, the torque compensator of the third
embodiment, the simulation observer, the regulatory control section, and
the torque synthesizer by a plurality of processors.
In the first embodiment of the invention, constructing the host control
section in due consideration of the characteristics of the regulatory
control section and the machine system enables preventing the vibration
and overshoot that may occur in the control performance in an electric
motor control device of the prior art when the host control section is
constructed based on a control sampling time period that differs from that
of regulatory control. When the host control section executes control with
a control sampling time period differing from that of regulatory control,
with processors having the same processing capability, the control process
of the regulatory control section can be carried out with a shorter
control sampling time period while the more complex control process is
executed in the host control section, and a more robust feedback
characteristics can thus be obtained. Further, the introduction of the
first torque compensator enables the realization of a simpler control
process of the regulatory control section and enables a the control
process of the regulatory control section to be carried out with a shorter
control sampling time period, and further, enables a simplification of the
construction of the host control section in due consideration of the
characteristics of the regulatory control section and machine system.
Finally, the introduction of the first torque compensator that processes
with a control sampling time period differing from that of the regulatory
control section enables the appropriate design for each of the regulatory
control section and the first torque compensator, can facilitate the
design of a control system that accords with the differing characteristics
of the machine system exhibited in the high-frequency region and
low-frequency region, and thus can realize superior control performance.
In the second embodiment of the invention, the use of only a second
simulation torque by the second torque compensator both enables a
reduction of the amount of data communication between the second torque
compensator and regulatory control section and also allows a simpler
construction of the second torque compensator. An electric motor control
device can therefore be realized with a shorter control sampling time
period with a processor having the same processing capability, thereby
enabling the prevention of the vibration and overshoot that may occur in
an electric motor control device of the prior art when the host control
section is constructed with a control sampling time period that differs
from that of the regulatory control, and moreover, allowing realization of
superior control performance.
In the third embodiment of the invention, the introduction of the
simulation observer allows a reduction of the noise included in the actual
response signal. As a result, the control gain of the host control
section, regulatory control section, and a second controller can be set to
a greater level, thereby enabling superior control performance.
In the fourth embodiment of the invention, the addition of a simulation
regulatory controller and a simulation signal processor to the host
control section of the prior art not only facilitates the realization of a
host control section operable on the basis of the second control sampling
time period by giving due consideration to the characteristics of the
regulatory control section and machine system, but also enables prevention
of the vibration and overshoot that may occur in an electric motor control
device of the prior art when the host control section is constructed with
a control sampling time period differing from that of the regulatory
control. As a result, superior control performance can be realized.
In the fifth embodiment of the invention, constructing the simulation model
by a rigid body system results in a simpler simulation model when the
mechanical resonance frequency of the mechanical system is high, and thus
enables not only the prevention of vibration and overshoot that may occur
in the control performance in an electric motor control device of the
prior art when the host control section is constructed with a control
sampling time period that differs from that of the regulatory control, but
also allows a reduction of the amount of computation required for the
electric motor control system.
In the sixth embodiment of the invention, constructing the simulation
regulatory controller by a P-P control system enables the realization of a
simpler simulation regulatory controller. Such a construction not only
enables the prevention of vibration and overshoot that may occur in the
electric motor control device of the prior art when the host control
section is constructed with a control sampling time period differing from
that of the regulatory control section, but also enables a reduction in
the amount of computation required for the electric motor control device.
In addition, the parameters of the simulation regulatory controller can be
more easily set.
In the seventh embodiment of the invention, constructing the host
controller by a P-P control system enables the realization of a simpler
host controller. Such a construction not only enables the prevention of
overshoot and vibration that may occur in the electric motor control
device of the prior art when the host control section is constructed with
a control sampling time period differing from that of the regulatory
control, but also enables a reduction of the amount of computation
required for the electric motor control device. In addition, the
parameters of the host controller can be more easily set.
In the eighth and ninth embodiments of the present invention, constructing
the regulatory control section by a P-P control system facilitates the
realization of the host controller. Such a construction not only enables
the prevention of vibration and overshoot that may occur in the electric
motor control device of the prior art when the host control section is
constructed with a control sampling time period differing from that of the
regulatory control, but also enables a reduction of the amount of
computation required for the electric motor control device. In addition,
the parameters of the regulatory control section can be more easily set.
Further, when the host control section is constructed in due consideration
of the regulatory control, the construction of the host control section
can be made simpler.
In the tenth and eleventh embodiments of the invention, the F1 or G1
simulation signal and the F2 or G2 simulation signal are generated at the
second control sampling time periods based on the first simulation
position signal and first simulation speed signal that are updated on the
basis of the first control sampling time period while taking into
consideration the difference between the first control sampling time
period and second control sampling time period, and these signals are
applied as input to the regulatory control section of the prior art,
thereby enabling smoothing of the second simulation torque signal. Such a
construction can prevent the vibration and overshoot that may occur in the
electric motor control device of the prior art when the host control
section is constructed with a control sampling time period that differs
from that of the regulatory control section.
In the twelfth embodiment of the invention, the addition of a command
filter not only enables a reduction of the vibration component included in
the second simulation torque signal but also enables the prevention of
vibration and overshoot that may occur in the electric motor control
device of the prior art when the host control section is constructed with
a control sampling time period that differs from that of regulatory
control.
In the thirteenth embodiment of the invention, the first simulation torque
signal that is updated at the first control sampling time periods is
generated at the second control sampling time periods while taking into
consideration the difference between the first control sampling time
period and second control sampling time period. This generated torque
signal is then supplied as input to the torque synthesizer of the prior
art as the I2 simulation signal to enable smoothing of the torque command
and thereby enable prevention of the vibration and overshoot that may
occur in the electric motor control device of the prior art when the host
control section is constructed with a control sampling time period that
differs from that of the regulatory control.
In the fourteenth embodiment of the invention, constructing the first
torque compensator by a P-P-I control system not only enables a prevention
of the vibration and overshoot that may occur in the electric motor
control device of the prior art when the host control section is
constructed with a control sampling time period that differs from that of
the regulatory control, but also enables a reduction of the amount of
calculation required for the electric motor control device. In addition,
the parameters of the first torque compensator can be more easily set.
In the fifteenth embodiment of the invention, constructing the second
torque compensator by an I control system not only enables the prevention
of vibration and overshoot that may occur in the electric motor control
device of the prior art when the host control section is constructed with
a control sampling time period that differs from that of the regulatory
control, but also enables a reduction in the amount of calculation
required for the electric motor control device. In addition, the
parameters of the second torque compensator can be more easily set.
In the sixteenth embodiment to eighteenth embodiment of the invention,
construction by a plurality of processors not only enables the prevention
of the vibration and overshoot that may occur in the electric motor
control device of the prior art when the host control section is
constructed with a control sampling time period that differs from that of
the regulatory control, but also enables a dramatic reduction of the
control sampling time of the electric motor control device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the prior art;
FIG. 2 is a block diagram showing working example 1 of the present
invention;
FIG. 3 is a block diagram showing working example 2 of the present
invention;
FIG. 4 is a block diagram showing working example 3 of the present
invention;
FIG. 5 is a block diagram showing working example 4 of the present
invention;
FIG. 6 is a block diagram showing working example 5 of the present
invention;
FIG. 7 is a block diagram showing working example 6 of the present
invention;
FIG. 8 is a block diagram showing working example 7 of the present
invention;
FIG. 9 is a block diagram showing working example 8 of the present
invention;
FIG. 10 is a block diagram showing working example 9 of the present
invention;
FIG. 11 is a block diagram showing working example 10 of the present
invention;
FIG. 12 is a block diagram showing working example 11 of the present
invention;
FIG. 13 is a block diagram showing working example 12 of the present
invention;
FIG. 14 is a block diagram showing working example 13 of the present
invention;
FIG. 15 is a block diagram showing working example 14 of the present
invention; and
FIG. 16 is a block diagram showing working example 15 of the present
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention are next described based on working
examples.
WORKING EXAMPLE 1
The working example 1 of the present invention will be set forth in detail
below.
We next refer to FIG. 2 regarding the details of working example 1 of the
present invention.
FIG. 2 is a block diagram showing an overall view of working example 1 of
the present invention. In FIG. 2, the working example of the present
invention comprises: machine system 5 comprising load machine 1, transfer
mechanism 2, electric motor 3, and power conversion circuit 4; actual
state observer 6, command generator 7, host control section 8, regulatory
control section 9, torque synthesizer 10, and first torque compensator 11.
Machine system 5, actual state observer 6, and command generator 7 are
identical to the machine system, the rotation detector and the command
generator of prior-art devices, respectively. .theta.ref is an actual
command signal that has been generated by command generator 7. .theta.m is
an actual response signal that has been generated by actual state observer
6.
Based on actual command signal .theta.ref, host control section 8 provides
first simulation position signal .theta.F, first simulation speed signal
.omega.F, and first simulation torque signal TFF with each second control
sampling time period t2.
Based on first simulation position signal .theta.F, first simulation speed
signal .omega.F, and actual response signal .theta.m, regulatory control
section 9 provides second simulation torque signal TFB with each first
control sampling time period t1.
Based on first simulation position signal .theta.F, first simulation speed
signal .omega.F, and actual response signal .theta.m, first torque
compensator 11 provides third simulation torque signal TD with each second
control sampling time period t2.
Based on first simulation torque signal TFF, second simulation torque
signal TFB, and third simulation torque signal TD, torque synthesizer 10
provides torque command Tref.
In host control section 8, first simulation position signal .theta.F, first
simulation speed signal .omega.F, and first simulation torque signal TFF
are generated by expressing the equations (1), (2), and (3) below in the
discrete-time representation with respect to second control sampling time
period t2.
.theta.F=[1/(T1*s.sup.2 +T2*s+1)]*.theta.ref (1)
.omega.F=[s/(T1*s.sup.2 +T2*s+1)]*.theta.ref (2)
TFF=[Jm*s.sup.2 /(T1*s.sup.2 +T2*s+1)]*.theta.ref (3)
Here, T1, T2 and Jm are set according to the characteristics of machine
system 5 and regulatory control section 9.
In first torque compensator 11, third simulation torque signal TD is
generated by expressing equation (4) below in discrete-time representation
with respect to second control sampling time period t2.
TD=[(K1*(.theta.F-.theta.m)-K2*(.omega.F-.omega.m)]/s, (4)
where K1 and K2 are the control gain.
In regulatory control section 9, the second simulation torque signal (TFB)
is generated by expressing equation (5) below in discrete-time
representation with respect to control sampling time period t1.
TFB=K3*(.theta.F-.theta.m)+K4*(.omega.F-.omega.m), (5)
where K3 and K4 are the control gain.
In torque synthesizer 10, torque commands are generated as follows with
each first control sampling time period t1:
Tref=TFF+TD+TFB (6)
WORKING EXAMPLE 2
We next refer to FIG. 3 to describe the details of working example 2 of the
present invention. FIG. 3 is a block diagram showing the overall
configuration of the present working example. In FIG. 3, the working
example of the present invention includes: machine system 5 that comprises
load machine 1, transfer mechanism 2, electric motor 3, and power
conversion circuit 4; actual state observer 6; command generator 7; host
control section 8; regulatory control section 9; torque synthesizer 10;
and second torque compensator 12.
Second torque compensator 12 provides third simulation torque signal TD
with each second control sampling time t2 based on second simulation
torque signal TFB.
In second torque compensator 12, third simulation torque signal TD is
generated by expressing equation (7) below in the discrete-time
representation with respect to second control sampling time period t2.
TD=K5*TFB/s (7)
WORKING EXAMPLE 3
We next refer to FIG. 4 to describe details regarding working example 3 of
the present invention.
FIG. 4 is a block diagram showing the overall configuration of this working
example. In FIG. 4, the working example of the present invention includes:
machine system 5 that comprises load machine 1, transfer mechanism 2,
electric motor 3, and power conversion circuit 4; actual state observer 6;
command generator 7; host control section 8; regulatory control section
14; torque synthesizer 10; simulation observer 13; and second torque
compensator 12.
Simulation observer 13 provides estimated position signal .theta.mh and
estimated speed signal .omega.mh at first control sampling time t1 based
on actual response signal .theta.m and torque command Tref.
Regulatory control section 14 provides second simulation torque signal TFB
with each first control sampling time period t1 based on first simulation
position signal .theta.F, first simulation speed signal .omega.F,
estimated position signal .theta.mh, and estimated speed signal .omega.mh.
In regulatory control section 14, second simulation torque signal TFB is
generated in accordance with equation (8).
TFB=K3*(.theta.F-.theta.mh)+K4(.omega.F-.omega.mh) (8)
In simulation observer 13, estimated position signal .theta.mh and
estimated speed signal .omega.mh are generated as follows: let k1 be the
sample counter value counted with each first control sampling time period
t1 and (k1) represent the value of the time variable at time t1*k1; then
e(k1)=.theta.m(k1)-.theta.mh(k1) (9)
.theta.mh(k1+1)=.theta.mh(k1)+.omega.mh(k1)*t1+L1*e(k1) (10)
.omega.mh(k1+1)=.omega.mh(k1)+Tref(k1)*t1/Jm+L2*e(k1) (11)
WORKING EXAMPLE 4
We next refer to FIG. 5 to explain the details of this working example.
FIG. 5 is a block diagram showing working example 4 of the present
invention. In FIG. 5, host control section 8 of the working example of the
present invention is provided with host controller 8a, simulation
regulatory controller 8b, adder 8d, simulation model 8c, and simulation
signal processor 8e.
Host controller 8a provides first simulation torque signal TFF based on
actual command signal .theta.ref, first simulation position signal
.theta.F, and first simulation speed signal .omega.F.
Simulation regulatory controller 8b provides fourth simulation signal SI4
based on first simulation position signal .theta.F and first simulation
speed signal .omega.F.
Adder 8d provides first simulation signal SI1 based on first simulation
torque signal TFF and fourth simulation signal SI4.
Simulation model 8c provides second simulation signal SI2 and third
simulation signal SI3 based on first simulation signal SI1. The contents
of simulation signals SI2 and SI3 will be explained later referring to
FIG. 6.
Simulation signal processor 8e provides first simulation position signal
.theta.F and first simulation speed signal .omega.F with each second
control sampling time period t2 based on second simulation signal SI2 and
the third simulation signal SI3.
In host controller 8a, first simulation torque signal TFF is generated as
follows:
TFF=K5*(.theta.ref-.theta.F)-K6*.theta.F (12)
In simulation regulatory controller 8b, fourth simulation signal SI4 is
generated as follows:
SI4=K7*.theta.F+K8*.omega.F (13)
In adder 8d, first simulation signal SI1 is generated as follows:
SI1=TFF-SI4 (14)
Second simulation signal SI2 and third simulation signal SI3 are generated
in simulation model 8c.
In simulation signal processor 8e, first simulation position signal
.theta.F and first simulation speed signal .omega.F are generated as
follows: let k2 be the sample counter value counted with each second
control sampling time period t2 (=1 ms), and (k2) represent the value of
time variable at time t2*k2; then
.theta.F(t)=SI2(k2*t2) (17)
.omega.F(t)=SI3(k2*t2), (18)
where
k2*t2.ltoreq.(k2+1)*t2 (19)
WORKING EXAMPLE 5
We next refer to FIG. 6 to explain the details of working example 5 of the
present invention. FIG. 6 is a block diagram showing this working example.
In FIG. 6, simulation model 8c of the working example of the present
invention comprises: subtracter 8c4, coefficient multiplier 8c5,
subtracter 8c6, coefficient multiplier 8c7, coefficient multiplier 8c1,
integrator 8c2, and integrator 8c3.
In subtracter 8c4, simulation signal SI32 is generated as follows:
SI32=SI1-SI2 (20)
In coefficient multiplier 8c5, the coefficient is set to Kp and simulation
signal SI29 is generated as follows:
SI29=Kp*SI32 (21)
In subtracter 8c6, simulation signal SI30 is generated as follows:
SI30=SI29-SI3 (22)
In coefficient multiplier 8c7, the coefficient is set to Kv, and simulation
signal SI31 is generated as follows:
SI31=Kv*SI30 (23)
In coefficient multiplier 8c1, the coefficient is set to 1/Jm and
simulation signal SI28 is generated as follows:
SI28=SI31/Jm (24)
Simulation signal SI3 is generated as follows:
SI3=SI28/s (25)
Simulation signal SI2 is generated as follows:
SI2=SI3/s (26)
WORKING EXAMPLE 6
We next refer to FIG. 7 to describe details regarding working example 6 of
the present invention. FIG. 7 is a block diagram showing the present
working example. In FIG. 7, simulation regulatory controller 8b of the
working example of the present invention is provided with coefficient
multiplier 8b1, adder 8b2, and coefficient multiplier 8b3.
In coefficient multiplier 8b1, the coefficient is set to Kp and simulation
signal SI5 is generated as follows:
SI5=Kp*.theta.F (27)
In adder 8b2, simulation signal SI6 is generated as follows:
SI6=.omega.F+SI5 (28)
In coefficient multiplier 8b3, the coefficient is set to Kv and simulation
signal SI4 is generated as follows:
SI4=Kv*SI6 (29)
WORKING EXAMPLE 7
We next refer to FIG. 8 to describe details regarding working example 7 of
the present invention. FIG. 8 is a block dia
