79 lines
3.5 KiB
C
79 lines
3.5 KiB
C
#ifndef PID_h
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#define PID_h
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#include "chtypes.h"
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//Constants used in some of the functions below
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#define PID_AUTOMATIC 1
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#define PID_MANUAL 0
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#define PID_DIRECT 0
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#define PID_REVERSE 1
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#define PID_ON_M 0
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#define PID_ON_E 1
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typedef struct {
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float kp; // * (P)roportional Tuning Parameter
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float ki; // * (I)ntegral Tuning Parameter
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float kd; // * (D)erivative Tuning Parameter
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float dispKp; // * we'll hold on to the tuning parameters in user-entered
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float dispKi; // format for display purposes
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float dispKd; //
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int direction;
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int pOn;
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float *input; // * Pointers to the Input, Output, and Setpoint variables
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float *output; // This creates a hard link between the variables and the
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float *setPoint; // PID, freeing the user from having to constantly tell us
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// what these values are. with pointers we'll just know.
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unsigned long lastTime;
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float outputSum;
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float lastInput;
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unsigned long sampleTime;
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float outMin;
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float outMax;
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bool inAuto;
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bool pOnE;
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} pidc_t;
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//commonly used functions **************************************************************************
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void pid_create(pidc_t* p, float* Input, float* Output, float* Setpoint, // * constructor. links the PID to the Input, Output, and
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float Kp, float Ki, float Kd, int POn, int Direction); // Setpoint. Initial tuning parameters are also set here.
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// (overload for specifying proportional mode)
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void pid_setMode(pidc_t* p, int mode); // * sets PID to either Manual (0) or Auto (non-0)
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bool pid_compute(pidc_t* p); // * performs the PID calculation. it should be
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// called every time loop() cycles. ON/OFF and
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// calculation frequency can be set using SetMode
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// SetsampleTime respectively
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void pid_setOutputLimits(pidc_t* p, float Min, float Max); // * clamps the output to a specific range. 0-255 by default, but
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// it's likely the user will want to change this depending on
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// the application
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//available but not commonly used functions ********************************************************
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void pid_setTunings(pidc_t* p, float Kp, float Ki, float Kd, int POn); // * While most users will set the tunings once in the
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// constructor, this function gives the user the option
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// of changing tunings during runtime for Adaptive control
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void pid_setDirection(pidc_t* p, int Direction); // * Sets the Direction, or "Action" of the controller. DIRECT
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// means the output will increase when error is positive. REVERSE
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// means the opposite. it's very unlikely that this will be needed
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// once it is set in the constructor.
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void pid_setSampleTime(pidc_t* p, int NewSampleTime); // * sets the frequency, in Milliseconds, with which
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// the PID calculation is performed. default is 100
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void pid_initialize(pidc_t* p);
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#endif
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