Robot apparatus, robot control method, program, and recording medium
AssigneeCanon Kabushiki Kaisha
InventorTsutomu Osaka
Life of this patent
Estimating the term…
Abstract
A robot apparatus includes a rectangular wave generating portion arranged on the output side of a speed reducer, and configured to generate first output pulse signals upon driving of a joint. A control portion includes calculating portions and a motor control portion. The motor control portion estimates an estimated joint angle using input pulse signals, and controls to operate a servo motor so that this estimated joint angle matches a target joint angle. The calculating portions calculate a torsion angle of the joint corresponding to a deviation amount between the first output pulse signals and a pulse waveform of an ideal state. The motor control portion controls to operate the servo motor so as to correct the estimated joint angle by the torsion angle.
Claims15
A robot apparatus comprising:
- a rotary motor;
- a speed reducer configured to decelerate an output of the rotary motor;
- a robot main body having a joint driven by the rotary motor via the speed reducer;
- a control portion configured to control driving of the joint by the rotary motor so that an angle of the joint matches a target joint angle;
- an input encoder portion arranged on an input side of the speed reducer, and configured to generate input pulse signals upon rotation of a rotating shaft of the rotary motor;
- and
- a rectangular wave generating portion arranged on an output side of the speed reducer, and configured to generate first output pulse signals according to an angle of the joint upon driving of the joint,
- wherein the control portion executes
- a first control process for estimating an angle of the joint in an ideal state in which the joint is free from any torsion from a rotation angle of the rotating shaft of the rotary motor indicated by the input pulse signals and a speed reduction ratio of the speed reducer, and controlling to operate the rotary motor so that an estimated joint angle matches the target joint angle,
- a torsion angle calculating process for calculating a torsion angle of the joint corresponding to a deviation amount between the first output pulse signals and a pulse waveform assumed to be obtained from the rectangular wave generating portion in the ideal state, and
- a correction control process for controlling to operate the rotary motor to correct the estimated joint angle by the torsion angle.
A robot control method for controlling a control portion of a robot apparatus, which comprises a rotary motor, a speed reducer configured to decelerate an output of the rotary motor, a robot main body having a joint driven by the rotary motor via the speed reducer, an input encoder portion arranged on an input side of the speed reducer, and configured to generate input pulse signals upon rotation of a rotating shaft of the rotary motor, and a rectangular wave generating portion arranged on an output side of the speed reducer, and configured to generate first output pulse signals according to an angle of the joint upon driving of the joint, to control driving of the joint by the rotary motor so that an angle of the joint matches a target joint angle,
- the method comprising:
- a first control step of controlling the control portion to estimate an angle of the joint in an ideal state in which the joint is free from any torsion from a rotation angle of the rotating shaft of the rotary motor indicated by the input pulse signals and a speed reduction ratio of the speed reducer, and to control to operate the rotary motor so that an estimated joint angle matches the target joint angle;
- a torsion angle calculating step of controlling the control portion to calculate a torsion angle of the joint corresponding to a deviation amount between the first output pulse signals and a pulse waveform assumed to be obtained from the rectangular wave generating portion in the ideal state;
- and
- a correction control step of controlling the control portion to control to operate the rotary motor to correct the estimated joint angle by the torsion angle.
Dependencies are inferred from the claim text.