Download Motion Controller/Driver
Transcript
7.2.1 Hardware And Software Requirements Hardware Requirements Tuning is best accomplished when the system response can be measured. This can be done with external monitoring devices but can introduce errors. The ESP6000 controller avoids this problem by providing an internal trace capability. When trace mode is activated, the controller records a number of different parameters. The parameters can include real instantaneous position, desired position, desired velocity, desired acceleration, DAC output value, etc. The sample interval can be set to one servo cycle or any multiple of it and the total number of samples can be up to 1000. This is a powerful feature that the user can take advantage of to get maximum performance out of the motion system. Software Requirements Users can write their own application(s) or use the ESP-tune.exe Windows utility. Refer to Section 4 for a detailed description of the utility and its operation. 7.2.2 Correcting Axis Oscillation There are three parameters that can cause oscillation. The most likely to induce oscillation is Ki, followed by Kp and Kd. Start by setting Ki to zero and reducing Kp and Kd by 50%. If oscillation does not stop, reduce Kp again. When the axis stops oscillating, system response is probably very soft. The following error may be quite large during motion and non-zero at stop. Continue tuning the PID with the procedures described in the next paragraph. 7.2.3 Correcting Following Error If the system is stable and you want to improve performance, start with the current PID parameters. The goal is to reduce following error during motion and to eliminate it at stop. Guidelines for further tuning (based on performance starting point and desired outcome) are provided in the following paragraphs. 7 - 2