涂 桂旺 / PID

test

Fork of PID by Bryce Williams

PID.h@2:07397aa513c6, 2015-11-24 (annotated)

Committer:
electromotivated
Date:
Tue Nov 24 00:17:55 2015 +0000
Revision:
2:07397aa513c6
Parent:
0:9a6f7aafe531
Child:
5:0cf2f6d13c71
Added new prototypes to header;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
electromotivated 0:9a6f7aafe531 1 #ifndef PID_H
electromotivated 0:9a6f7aafe531 2 #define PID_H
electromotivated 0:9a6f7aafe531 3 #include "mbed.h"
electromotivated 0:9a6f7aafe531 4 #include <algorithm>
electromotivated 0:9a6f7aafe531 5
electromotivated 0:9a6f7aafe531 6 /*
electromotivated 0:9a6f7aafe531 7 Bryce Williams 11/19/2015
electromotivated 0:9a6f7aafe531 8
electromotivated 0:9a6f7aafe531 9 PID Controller Class based on Brett Beauregard's Arduino PID Library
electromotivated 0:9a6f7aafe531 10 and PID blog post.
electromotivated 0:9a6f7aafe531 11
electromotivated 0:9a6f7aafe531 12 Brett Beauregard's blog post explains the PID code implementation very well
electromotivated 0:9a6f7aafe531 13 and discusses why the actual equation is a bit different than the classical
electromotivated 0:9a6f7aafe531 14 equation, i.e. he explains and implements how to overcome windup, dervative
electromotivated 0:9a6f7aafe531 15 kick, etc. This class uses the same implementation, but adds interrupt
electromotivated 0:9a6f7aafe531 16 driven computation.
electromotivated 0:9a6f7aafe531 17
electromotivated 0:9a6f7aafe531 18 Reference Links:
electromotivated 0:9a6f7aafe531 19 1. Arduion Library:
electromotivated 0:9a6f7aafe531 20 (http://playground.arduino.cc/Code/PIDLibrary)
electromotivated 0:9a6f7aafe531 21 2. Brett Beauregard's PID Blog:
electromotivated 0:9a6f7aafe531 22 (http://brettbeauregard.com/blog/2011/04/improving-the-beginners-
electromotivated 0:9a6f7aafe531 23 pid-introduction/)
electromotivated 0:9a6f7aafe531 24 */
electromotivated 0:9a6f7aafe531 25
electromotivated 0:9a6f7aafe531 26 class PID{
electromotivated 0:9a6f7aafe531 27 public:
electromotivated 0:9a6f7aafe531 28 /*
electromotivated 0:9a6f7aafe531 29 Constructor for PID objects.
electromotivated 0:9a6f7aafe531 30
electromotivated 0:9a6f7aafe531 31 Note: PID objects use given pointers, ie setpoint,
electromotivated 0:9a6f7aafe531 32 feedback, output inside interrupts. When reading/ modifying
electromotivated 0:9a6f7aafe531 33 these vars make sure we don't have possible read/write
electromotivated 0:9a6f7aafe531 34 conflicts if the interrupt fires. Either ensure reads/writes
electromotivated 0:9a6f7aafe531 35 are atomic operations, or call the stop() method perform the
electromotivated 0:9a6f7aafe531 36 read/write and then call the start() method.
electromotivated 0:9a6f7aafe531 37 */
electromotivated 0:9a6f7aafe531 38 PID(float* setpoint, float* feedback, float* output,
electromotivated 0:9a6f7aafe531 39 float output_lower, float output_upper,
electromotivated 0:9a6f7aafe531 40 float kp, float ki, float kd, float Ts);
electromotivated 0:9a6f7aafe531 41 /*
electromotivated 0:9a6f7aafe531 42 Starts PID Controller; Attaches sample() as callback to Ticker
electromotivated 0:9a6f7aafe531 43 sample_timer and starts the interrupt
electromotivated 0:9a6f7aafe531 44 */
electromotivated 0:9a6f7aafe531 45 void start();
electromotivated 0:9a6f7aafe531 46 /*
electromotivated 0:9a6f7aafe531 47 Stops PID Contoller; detaches callback from Ticker sample_timer.
electromotivated 0:9a6f7aafe531 48 Allows manual setting of output.
electromotivated 0:9a6f7aafe531 49 */
electromotivated 0:9a6f7aafe531 50 void stop();
electromotivated 0:9a6f7aafe531 51 /*
electromotivated 0:9a6f7aafe531 52 Increments/ decrements Gain values and Sample time
electromotivated 0:9a6f7aafe531 53 by the given value. Gives a simple method to
electromotivated 0:9a6f7aafe531 54 programatically step through different values; just put in a
electromotivated 0:9a6f7aafe531 55 loop and go
electromotivated 0:9a6f7aafe531 56 @param delta_"name" The value that will be added to its currently set value
electromotivated 0:9a6f7aafe531 57 */
electromotivated 0:9a6f7aafe531 58 // void adjust_parameters(float delta_kp, float delta_ki, float delta_kd, float delta Ts);
electromotivated 0:9a6f7aafe531 59 /*
electromotivated 0:9a6f7aafe531 60 Overwrite Gain and Sample Time parameters with new
electromotivated 0:9a6f7aafe531 61 values
electromotivated 0:9a6f7aafe531 62 Note: sample_timer interrupt is disabled during update
electromotivated 0:9a6f7aafe531 63 to avoid synch issues.
electromotivated 0:9a6f7aafe531 64
electromotivated 0:9a6f7aafe531 65 */
electromotivated 0:9a6f7aafe531 66 void set_parameters(float kp, float ki, float kd, float Ts);
electromotivated 0:9a6f7aafe531 67
electromotivated 2:07397aa513c6 68 float getKp();
electromotivated 2:07397aa513c6 69 float getKi();
electromotivated 2:07397aa513c6 70 float getKd();
electromotivated 2:07397aa513c6 71 float getTs();
electromotivated 2:07397aa513c6 72
electromotivated 0:9a6f7aafe531 73 /*
electromotivated 0:9a6f7aafe531 74 returns current error
electromotivated 0:9a6f7aafe531 75 */
electromotivated 0:9a6f7aafe531 76 float getError();
electromotivated 0:9a6f7aafe531 77
electromotivated 0:9a6f7aafe531 78 private:
electromotivated 0:9a6f7aafe531 79 float _kp, _ki, _kd; // PID Gain values
electromotivated 0:9a6f7aafe531 80 float _Ts; // Sample time is seconds
electromotivated 0:9a6f7aafe531 81 float* _setpoint; // Pointer to setpoint value
electromotivated 0:9a6f7aafe531 82 float* _feedback; // Pointer to sensor feedback value (sensor input)
electromotivated 0:9a6f7aafe531 83 float* _output; // Pointer to control output value
electromotivated 0:9a6f7aafe531 84 float _output_lower; // Ouput Lower Limit
electromotivated 0:9a6f7aafe531 85 float _output_upper; // Output Upper Limit
electromotivated 0:9a6f7aafe531 86
electromotivated 0:9a6f7aafe531 87 float i_accumulator; // Integral Term accumulator
electromotivated 0:9a6f7aafe531 88 float last_feedback; // Previous feedback value
electromotivated 0:9a6f7aafe531 89 float error; // Feedback error term
electromotivated 0:9a6f7aafe531 90 Ticker sample_timer; // Generates the sample time interrupt and calls sample()
electromotivated 0:9a6f7aafe531 91 /*
electromotivated 0:9a6f7aafe531 92 sample() performs next sample calculationand updates command value
electromotivated 0:9a6f7aafe531 93 */
electromotivated 0:9a6f7aafe531 94 void sample();
electromotivated 0:9a6f7aafe531 95 /*
electromotivated 0:9a6f7aafe531 96 Clips value to lower/ uppper
electromotivated 0:9a6f7aafe531 97 @param value The value to clip
electromotivated 0:9a6f7aafe531 98 @param lower The mininum allowable value
electromotivated 0:9a6f7aafe531 99 @param upper The maximum allowable value
electromotivated 0:9a6f7aafe531 100 @return The resulting clipped value
electromotivated 0:9a6f7aafe531 101 */
electromotivated 0:9a6f7aafe531 102 float clip(float value, float lower, float upper);
electromotivated 0:9a6f7aafe531 103 };
electromotivated 0:9a6f7aafe531 104
electromotivated 0:9a6f7aafe531 105 #endif