Method and apparatus for tuning a motion control system

A method for tuning a motion control system of the type including a command device for generating position command signals, an actuator for displacing a physical element to a desired location in response to drive signals, a sensor for generating feedback signals representative of the position of the physical element and a controller coupled to the command device, the sensor and the actuator for processing the command and feedback signals and generating drive signals for driving the actuator in response to the command and feedback signals, the controller multiplying at least one parameter error signal derived from the command and feedback signals by a gain value to generate the drive signals, the method comprising the steps of:

• (a) applying a first drive signal at a predetermined level to the actuator to accelerate the actuator to a predetermined velocity;
• (b) applying a second drive signal at a predetermined level to the actuator to decelerate the actuator;
• (c) monitoring feedback signals during the acceleration and deceleration and recording acceleration and deceleration times;
• and
• (d) generating the gain value based upon a value representative of system inertia derived from the predetermined levels of the first and second drive signals, the acceleration and deceleration times and the feedback signals.

A method for tuning a motion control system of the type including a command device for generating position command signals, an actuator for displacing a physical element to a desired location in response to drive signals, a sensor for generating feedback signals representative of the position of the physical element and a controller coupled to the command device, the sensor and the actuator for processing the command and feedback signals and generating drive signals for driving the actuator in response to the command and feedback signals, the method comprising the steps of:

• (a) applying a first drive signal at a predetermined level to the actuator to accelerate the actuator to a predetermined velocity;
• (b) applying a second drive signal at a predetermined level to the actuator to decelerate the actuator;
• (c) monitoring feedback signals during the acceleration and deceleration and recording acceleration and deceleration times;
• (d) generating a position loop bandwidth value;
• and
• (e) generating values representative of system gains and dynamic characteristics based upon the predetermined levels of the first and second drive signals, the acceleration and deceleration times and the position loop bandwidth value.

An apparatus for tuning a motion control system of the type including an input device for generating position command signals, an actuator for displacing a physical element to a desired location, a drive circuit for driving the actuator in response to control signals, a sensor for generating feedback signals representative of the position of the physical element and a controller coupled to the input device, the sensor and the drive circuit for processing the command and feedback signals and generating control signals for driving the actuator in response to the command and feedback signals, the controller multiplying at least one parameter error signal derived from the command and feedback signals by a gain value to generate the control signals, the apparatus comprising:

• a control signal generating circuit coupled to the drive circuit for generating and applying control signals to the drive circuit to accelerate and decelerate the actuator during a tuning sequence, the tuning sequence including a single, unidirectional motion event wherein the actuator is accelerated in a predetermined direction and then decelerated in the predetermined direction;
• a processing circuit coupled to the sensor and to the control signal generating circuit for monitoring the feedback signals during the tuning sequence and for generating a signal representative of the gain value based upon the control signals applied during the tuning sequence and the feedback signals monitored during the tuning sequence;
• and
• a memory circuit for storing the signal representative of the gain value.