CONTROL APPARATUS, CONTROL METHOD, AND CONTROL PROGRAM FOR ELASTIC ACTUATOR DRIVE MECHANISM

• US 20130000480A1
• Filed: 09/13/2012
• Published: 01/03/2013
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Okazaki, Yasunao, KOMATSU, Mayumi
• Granted Patent: US 8,650,868 B2
• Time in Patent Office: Days
• US Class Current: 92/48
• CPC Class Codes: B25J 9/142 comprising inflatable bodies
• CPC Class Codes: B25J 9/1615 characterised by special kind of manipulator, e.g. planar, scara, gantry, cantilever, space, closed chain, passive/active joints and tendon driven manipulators
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: F15B 11/16 with two or more servomotors
• CPC Class Codes: F15B 2211/7052 Single-acting output members
• CPC Class Codes: F15B 2211/7107 the output members being mechanically linked
• CPC Class Codes: G05B 2219/39454 Rubber actuator, two muscle drive, one for extension other for traction
• CPC Class Codes: G05B 2219/39462 Pneumatic actuator, imitates human muscle
• CPC Class Codes: G05B 23/0243 model based detection method, e.g. first-principles knowledge model

Abstract

There is provided an abnormality determination unit that determines whether or not an output measurement unit is abnormal, in order to determine abnormality of the output measurement unit. When the output measurement unit is abnormal, the operation of an elastic actuator is controlled not in accordance with a measurement result of the output measurement unit but in accordance with an internal state model.

Claims

1. A control apparatus of an elastic actuator drive mechanism, comprising:

an abnormality determination unit that determines whether or not an output measurement unit that measures an output of an elastic actuator is abnormal;

a normal case operation control unit that controls the elastic actuator drive mechanism in accordance with an output of the output measurement unit when the abnormality determination unit determines that the output measurement unit is normal;

an abnormal case operation control unit that controls the elastic actuator drive mechanism in accordance with an internal state model when the abnormality determination unit determines that the output measurement unit is abnormal; and

a control unit that operates the normal case operation control unit when the abnormality determination unit determines that the output measurement unit is normal, and that switches from the normal case operation control unit to the abnormal case operation control unit so as to operate the abnormal case operation control unit when the abnormality determination unit determines that the output measurement unit is abnormal;

wherein

the normal case operation control unit comprises;

a first desired output unit that outputs a desired value of the output of the elastic actuator; and

a torque control unit that calculates a desired joint torque in accordance with an output of the first desired output unit and the output of the output measurement unit,

the normal case operation control unit controls the elastic actuator drive mechanism in accordance with the desired joint torque calculated by the torque control unit,

the abnormal case operation control unit comprises;

a second desired output unit that outputs a desired value of the output of the elastic actuator; and

a desired internal state information acquisition unit that acquires desired internal state information on the elastic actuator in accordance with a desired value of the output of the second desired output unit and the internal state model, and

the abnormal case operation control unit controls the elastic actuator drive mechanism not in accordance with a measurement result of the output of the elastic actuator but in accordance with the desired internal state information acquired by the desired internal state information acquisition unit so that the elastic actuator is operated continuously.

2. The control apparatus according to claim 1, wherein the desired internal state information acquisition unit of the abnormal case operation control unit comprises a first desired internal state calculation unit that calculates desired internal state information in accordance with the desired value of the output of the second desired output unit and the internal state model, and the elastic actuator drive mechanism is controlled in accordance with the desired internal state information calculated by the first desired internal state calculation unit so that the elastic actuator is operated continuously.

3. The control apparatus according to claim 1, wherein the desired internal state information acquisition unit of the abnormal case operation control unit comprises:

an output estimation unit that estimates the output of the elastic actuator in accordance with the internal state model and the internal state information on the elastic actuator; and

a second desired internal state information calculation unit that calculates desired internal state information in accordance with the output of the elastic actuator estimated by the output estimation unit and the desired value of the output of the second desired output unit; and

the elastic actuator drive mechanism is controlled in accordance with the desired internal state information calculated in accordance with the output of the elastic actuator estimated by the output estimation unit, so that the elastic actuator is operated continuously.

4. The control apparatus according to claim 1, wherein the abnormality determination unit compares information on a relationship between the output of the output measurement unit and an internal state from an internal state measurement unit that measures an internal state of the elastic actuator, with information on a relationship between the output of the elastic actuator and the internal state of the elastic actuator in an internal state model for the output measurement unit being normal, to determine whether or not the output measurement unit is abnormal.

5. The control apparatus of an elastic actuator drive mechanism according to claim 1, wherein the second desired output unit in the abnormal case operation control unit and the first desired output unit in the normal case operation control unit output desired values of different outputs of the elastic actuator, respectively, to control by the abnormal case operation control unit, when the abnormal case operation control unit is operated, such that the elastic actuator moves to a safety position and then stops.

6. The control apparatus of an elastic actuator drive mechanism according to claim 1, wherein the elastic actuator is a fluid pressure actuator.

7. A method of controlling an elastic actuator drive mechanism, the method comprising:

determining, by an abnormality determination unit, whether or not an output measurement unit that measures an output of an elastic actuator is abnormal;

controlling, by a normal case operation control unit, the elastic actuator drive mechanism in accordance with an output of the output measurement unit, when the abnormality determination unit determines that the output measurement unit is normal, or

controlling, by an abnormal case operation control unit, the elastic actuator drive mechanism in accordance with an internal state model, when the abnormality determination unit determines that the output measurement unit is abnormal;

operating, by a control unit, the normal case operation control unit when the abnormality determination unit determines that the output measurement unit is normal, or switching from the normal case operation control unit to the abnormal case operation control unit to operate the abnormal case operation control unit by the control unit, when the abnormality determination unit determines that the output measurement unit is abnormal;

when the normal case operation control unit is operated,

outputting, from a first desired output unit, a desired value of the output of the elastic actuator, and

calculating, by a torque control unit, a desired joint torque in accordance with an output of the first desired output unit and the output of the output measurement unit, to control the elastic actuator drive mechanism in accordance with the desired joint torque calculated by the torque control unit; and

when the abnormal case operation control unit is operated,

outputting, from a second desired output unit, a desired value of the output of the elastic actuator, and

acquiring, by a desired internal state information acquisition unit, desired internal state information on the elastic actuator in accordance with the desired value of the output of the second desired output unit and the internal state model, to control the elastic actuator drive mechanism not in accordance with a measurement result of the output of the elastic actuator but in accordance with the desired internal state information acquired by the desired internal state information acquisition unit so that the elastic actuator is operated continuously.

8. A control program for an elastic actuator drive mechanism, the program causing a computer to execute functions of:

determining, by an abnormality determination unit, whether or not an output measurement unit that measures an output of an elastic actuator is abnormal;

controlling, by a normal case operation control unit, the elastic actuator drive mechanism in accordance with an output of the output measurement unit, when the abnormality determination unit determines that the output measurement unit is normal;

controlling, by an abnormal case operation control unit, the elastic actuator drive mechanism in accordance with an internal state model, when the abnormality determination unit determines that the output measurement unit is abnormal;

operating, by a control unit, the normal case operation control unit when the abnormality determination unit determines that the output measurement unit is normal, or switching from the normal case operation control unit to the abnormal case operation control unit to operate the abnormal case operation control unit by the control unit,

when the abnormality determination unit determines that the output measurement unit is abnormal;

when the normal case operation control unit is operated,

outputting, from a first desired output unit, a desired value of the output of the elastic actuator, and

calculating, by a torque control unit, a desired joint torque in accordance with an output of the first desired output unit and the output of the output measurement unit, to control the elastic actuator drive mechanism in accordance with the desired joint torque calculated by the torque control unit; and

when the abnormal case operation control unit is operated,

outputting, from a second desired output unit, a desired value of the output of the elastic actuator, and

acquiring, by a desired internal state information acquisition unit, desired internal state information on the elastic actuator in accordance with the desired value of the output of the second desired output unit and the internal state model, to control the elastic actuator drive mechanism not in accordance with a measurement result of the output of the elastic actuator but in accordance with the desired internal state information acquired by the desired internal state information acquisition unit so that the elastic actuator is operated continuously.