Parallel drive system
To provide a parallel drive system that can reduce vibrations of an arm member and can realize positioning at a high speed even when a slave servomotor does not have a position detector, at a low cost. To achieve this object, a parallel drive system of the invention includes: a master servomotor and a slave servomotor that include linearly-moving movable units that are arranged in parallel to each other, respectively; and an arm member that forms a bridge between the two movable units. The system includes: a position detector detecting position information on the movable unit of the master servomotor; an acceleration sensor detecting acceleration information on the movable unit of the slave servomotor; a master servo amplifier controlling the master servomotor based on the position information; and a slave servo amplifier controlling the slave servomotor based on the position information and the acceleration information.
1. A parallel drive system comprising:
a first actuator and a second actuator that include linearly-moving movable units that are arranged in parallel to each other, respectively; and
an arm member that forms a bridge between the movable unit of the first actuator and the movable unit of the second actuator, wherein the parallel drive system further comprises:
a position detection unit that detects position information on the movable unit of the first actuator;
an acceleration detection unit that detects acceleration information on the movable unit of the second actuator;
a first control unit that controls the first actuator based on the position information; and
a second control unit that controls the second actuator based on the position information and the acceleration information, wherein the second control unit includes:
a first speed conversion unit that converts the position information into first speed information,
a second speed conversion unit that converts the acceleration information into second speed information, and
a speed synthesizer that synthesizes the first speed information and the second speed information into a synthesized speed.
2. The parallel drive system according to claim 1 , wherein the first and second actuators are linear servomotors, the first and second control units are servo amplifiers, and the position detection unit is a linear scale.
3. The parallel drive system according to claim 1 , wherein the speed synthesizer includes:
a subtraction unit that subtracts the second speed information from the first speed information;
a low-pass filter that has a predetermined cutoff frequency, and receives an output from the subtraction unit; and
an addition unit that adds an output from the low-pass filter to the second speed information to generate the synthesized speed.
4. The parallel drive system according to claim 1 , wherein the speed synthesizer includes:
a low-pass filter that has a predetermined cutoff frequency, and receives the first speed information;
a high-pass filter that has a predetermined cutoff frequency, and receives the second speed information; and
an addition unit that adds an output from the low-pass filter to an output from the high-pass filter to generate the synthesized speed.
5. A parallel drive system comprising:
a first actuator and a second actuator that include linearly-moving movable units that are arranged in parallel to each other, respectively; and
an arm member that forms a bridge between the movable unit of the first actuator and the moveable unit of the second actuator, wherein
the parallel drive system further comprises:
a position detection unit that detects position information on the moveable unit of the first actuator;
an acceleration detection unit that detects acceleration information on the movable unit of the second actuator;
a first control unit that controls the first actuator based on the position information; and
a second control unit that controls the second actuator based on the position information and the acceleration information, and wherein
the second control unit is configured to:
further receive a control signal for controlling a torque of the first actuator from the first control unit;
have a torque calculation unit that calculates a corrected torque based on the position information and the acceleration information; and
control the second actuator based on an output from the torque calculation unit and the control signal.