| ??? 11/27/04 12:23 Read: times |
#82073 - Another Shortcut Responding to: ???'s previous message |
Kuldeep,
Another shortcut I've recently learned while using a PID to control a Peltier device in a thermal control loop is to use two look up tables, one for heating and one for cooling (the device is assymetric in it's effectiveness). The look up tables are used as a 'base' value for computing the P, I and D contributions to the total PID output. The P, I and D contributions are shifted right by a number of bits to give the proper relative weight, thereby achieving the desired reponse. The individual contributions are added together to obtain the totoal PID ouput. By computing the individual contributions, the algorithm also incorporates a limiting function on the I path to eliminate 'wind up'. If right-shifting alone does not give the desired reponse, consider doing a shift and add. Cheers, Bruce |
| Topic | Author | Date |
| help about pid | 01/01/70 00:00 | |
| Floating point? | 01/01/70 00:00 | |
| Keil floating-point performance | 01/01/70 00:00 | |
| Search the forum | 01/01/70 00:00 | |
| Floating Point Vs Mixed point | 01/01/70 00:00 | |
| You mean Fixed Point | 01/01/70 00:00 | |
| Mixed not Fixed | 01/01/70 00:00 | |
| Warnings about Floating Point | 01/01/70 00:00 | |
| Shortcuts | 01/01/70 00:00 | |
| Implied aka Fixed point | 01/01/70 00:00 | |
| Another Shortcut | 01/01/70 00:00 | |
| Answering the question | 01/01/70 00:00 | |
| Autotunning? | 01/01/70 00:00 | |
| PID Tricks and Tuning | 01/01/70 00:00 | |
| Great Stuff ! | 01/01/70 00:00 | |
| I followed your idea... | 01/01/70 00:00 | |
| Another couple tricks | 01/01/70 00:00 | |
| tests | 01/01/70 00:00 | |
limit cycle tuning | 01/01/70 00:00 | |
| PID to control a Peltier | 01/01/70 00:00 | |
| An idea to try | 01/01/70 00:00 | |
| very fast 20ms ??? | 01/01/70 00:00 | |
| 20.000, not 2000. | 01/01/70 00:00 | |
| very fast 20ms ??? | 01/01/70 00:00 | |
| in points... | 01/01/70 00:00 |