px4_autopilot/apps/controllib/blocks.hpp

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/**
 * @file blocks.h
 *
 * Controller library code
 */

#pragma once

#include <assert.h>
#include <time.h>
#include <stdlib.h>
#include <mathlib/math/test/test.hpp>

#include "block/Block.hpp"
#include "block/BlockParam.hpp"

namespace control
{

int __EXPORT basicBlocksTest();

/**
 * A limiter/ saturation.
 * The output of update is the input, bounded
 * by min/max.
 */
class __EXPORT BlockLimit : public Block
{
public:
// methods
	BlockLimit(SuperBlock *parent, const char *name) :
		Block(parent, name),
		_min(this, "MIN"),
		_max(this, "MAX")
	{};
	virtual ~BlockLimit() {};
	float update(float input);
// accessors
	float getMin() { return _min.get(); }
	float getMax() { return _max.get(); }
protected:
// attributes
	BlockParam<float> _min;
	BlockParam<float> _max;
};

int __EXPORT blockLimitTest();

/**
 * A symmetric limiter/ saturation.
 * Same as limiter but with only a max, is used for
 * upper limit of +max, and lower limit of -max
 */
class __EXPORT BlockLimitSym : public Block
{
public:
// methods
	BlockLimitSym(SuperBlock *parent, const char *name) :
		Block(parent, name),
		_max(this, "MAX")
	{};
	virtual ~BlockLimitSym() {};
	float update(float input);
// accessors
	float getMax() { return _max.get(); }
protected:
// attributes
	BlockParam<float> _max;
};

int __EXPORT blockLimitSymTest();

/**
 * A low pass filter as described here:
 * http://en.wikipedia.org/wiki/Low-pass_filter.
 */
class __EXPORT BlockLowPass : public Block
{
public:
// methods
	BlockLowPass(SuperBlock *parent, const char *name) :
		Block(parent, name),
		_state(0),
		_fCut(this, "") // only one parameter, no need to name
	{};
	virtual ~BlockLowPass() {};
	float update(float input);
// accessors
	float getState() { return _state; }
	float getFCut() { return _fCut.get(); }
	void setState(float state) { _state = state; }
protected:
// attributes
	float _state;
	BlockParam<float> _fCut;
};

int __EXPORT blockLowPassTest();

/**
 * A high pass filter as described here:
 * http://en.wikipedia.org/wiki/High-pass_filter.
 */
class __EXPORT BlockHighPass : public Block
{
public:
// methods
	BlockHighPass(SuperBlock *parent, const char *name) :
		Block(parent, name),
		_u(0),
		_y(0),
		_fCut(this, "") // only one parameter, no need to name
	{};
	virtual ~BlockHighPass() {};
	float update(float input);
// accessors
	float getU() {return _u;}
	float getY() {return _y;}
	float getFCut() {return _fCut.get();}
	void setU(float u) {_u = u;}
	void setY(float y) {_y = y;}
protected:
// attributes
	float _u; /**< previous input */
	float _y; /**< previous output */
	BlockParam<float> _fCut; /**< cut-off frequency, Hz */
};

int __EXPORT blockHighPassTest();

/**
 * A rectangular integrator.
 * A limiter is built into the class to bound the
 * integral's internal state. This is important
 * for windup protection.
 * @see Limit
 */
class __EXPORT BlockIntegral: public SuperBlock
{
public:
// methods
	BlockIntegral(SuperBlock *parent, const char *name) :
		SuperBlock(parent, name),
		_y(0),
		_limit(this, "") {};
	virtual ~BlockIntegral() {};
	float update(float input);
// accessors
	float getY() {return _y;}
	float getMax() {return _limit.getMax();}
	void setY(float y) {_y = y;}
protected:
// attributes
	float _y; /**< previous output */
	BlockLimitSym _limit; /**< limiter */
};

int __EXPORT blockIntegralTest();

/**
 * A trapezoidal integrator.
 * http://en.wikipedia.org/wiki/Trapezoidal_rule
 * A limiter is built into the class to bound the
 * integral's internal state. This is important
 * for windup protection.
 * @see Limit
 */
class __EXPORT BlockIntegralTrap : public SuperBlock
{
public:
// methods
	BlockIntegralTrap(SuperBlock *parent, const char *name) :
		SuperBlock(parent, name),
		_u(0),
		_y(0),
		_limit(this, "") {};
	virtual ~BlockIntegralTrap() {};
	float update(float input);
// accessors
	float getU() {return _u;}
	float getY() {return _y;}
	float getMax() {return _limit.getMax();}
	void setU(float u) {_u = u;}
	void setY(float y) {_y = y;}
protected:
// attributes
	float _u; /**< previous input */
	float _y; /**< previous output */
	BlockLimitSym _limit; /**< limiter */
};

int __EXPORT blockIntegralTrapTest();

/**
 * A simple derivative approximation.
 * This uses the previous and current input.
 * This has a built in low pass filter.
 * @see LowPass
 */
class __EXPORT BlockDerivative : public SuperBlock
{
public:
// methods
	BlockDerivative(SuperBlock *parent, const char *name) :
		SuperBlock(parent, name),
		_u(0),
		_lowPass(this, "LP")
	{};
	virtual ~BlockDerivative() {};
	float update(float input);
// accessors
	void setU(float u) {_u = u;}
	float getU() {return _u;}
	float getLP() {return _lowPass.getFCut();}
protected:
// attributes
	float _u; /**< previous input */
	BlockLowPass _lowPass; /**< low pass filter */
};

int __EXPORT blockDerivativeTest();

/**
 * A proportional controller.
 * @link http://en.wikipedia.org/wiki/PID_controller
 */
class __EXPORT BlockP: public Block
{
public:
// methods
	BlockP(SuperBlock *parent, const char *name) :
		Block(parent, name),
		_kP(this, "") // only one param, no need to name
	{};
	virtual ~BlockP() {};
	float update(float input) {
		return getKP() * input;
	}
// accessors
	float getKP() { return _kP.get(); }
protected:
	BlockParam<float> _kP;
};

int __EXPORT blockPTest();

/**
 * A proportional-integral controller.
 * @link http://en.wikipedia.org/wiki/PID_controller
 */
class __EXPORT BlockPI: public SuperBlock
{
public:
// methods
	BlockPI(SuperBlock *parent, const char *name) :
		SuperBlock(parent, name),
		_integral(this, "I"),
		_kP(this, "P"),
		_kI(this, "I")
	{};
	virtual ~BlockPI() {};
	float update(float input) {
		return getKP() * input +
		       getKI() * getIntegral().update(input);
	}
// accessors
	float getKP() { return _kP.get(); }
	float getKI() { return _kI.get(); }
	BlockIntegral &getIntegral() { return _integral; }
private:
	BlockIntegral _integral;
	BlockParam<float> _kP;
	BlockParam<float> _kI;
};

int __EXPORT blockPITest();

/**
 * A proportional-derivative controller.
 * @link http://en.wikipedia.org/wiki/PID_controller
 */
class __EXPORT BlockPD: public SuperBlock
{
public:
// methods
	BlockPD(SuperBlock *parent, const char *name) :
		SuperBlock(parent, name),
		_derivative(this, "D"),
		_kP(this, "P"),
		_kD(this, "D")
	{};
	virtual ~BlockPD() {};
	float update(float input) {
		return getKP() * input +
		       getKD() * getDerivative().update(input);
	}
// accessors
	float getKP() { return _kP.get(); }
	float getKD() { return _kD.get(); }
	BlockDerivative &getDerivative() { return _derivative; }
private:
	BlockDerivative _derivative;
	BlockParam<float> _kP;
	BlockParam<float> _kD;
};

int __EXPORT blockPDTest();

/**
 * A proportional-integral-derivative controller.
 * @link http://en.wikipedia.org/wiki/PID_controller
 */
class __EXPORT BlockPID: public SuperBlock
{
public:
// methods
	BlockPID(SuperBlock *parent, const char *name) :
		SuperBlock(parent, name),
		_integral(this, "I"),
		_derivative(this, "D"),
		_kP(this, "P"),
		_kI(this, "I"),
		_kD(this, "D")
	{};
	virtual ~BlockPID() {};
	float update(float input) {
		return getKP() * input +
		       getKI() * getIntegral().update(input) +
		       getKD() * getDerivative().update(input);
	}
// accessors
	float getKP() { return _kP.get(); }
	float getKI() { return _kI.get(); }
	float getKD() { return _kD.get(); }
	BlockIntegral &getIntegral() { return _integral; }
	BlockDerivative &getDerivative() { return _derivative; }
private:
// attributes
	BlockIntegral _integral;
	BlockDerivative _derivative;
	BlockParam<float> _kP;
	BlockParam<float> _kI;
	BlockParam<float> _kD;
};

int __EXPORT blockPIDTest();

/**
 * An output trim/ saturation block
 */
class __EXPORT BlockOutput: public SuperBlock
{
public:
// methods
	BlockOutput(SuperBlock *parent, const char *name) :
		SuperBlock(parent, name),
		_trim(this, "TRIM"),
		_limit(this, ""),
		_val(0) {
		update(0);
	};
	virtual ~BlockOutput() {};
	void update(float input) {
		_val = _limit.update(input + getTrim());
	}
// accessors
	float getMin() { return _limit.getMin(); }
	float getMax() { return _limit.getMax(); }
	float getTrim() { return _trim.get(); }
	float get() { return _val; }
private:
// attributes
	BlockParam<float> _trim;
	BlockLimit _limit;
	float _val;
};

int __EXPORT blockOutputTest();

/**
 * A uniform random number generator
 */
class __EXPORT BlockRandUniform: public Block
{
public:
// methods
	BlockRandUniform(SuperBlock *parent,
			 const char *name) :
		Block(parent, name),
		_min(this, "MIN"),
		_max(this, "MAX") {
		// seed should be initialized somewhere
		// in main program for all calls to rand
		// XXX currently in nuttx if you seed to 0, rand breaks
	};
	virtual ~BlockRandUniform() {};
	float update() {
		static float rand_max = MAX_RAND;
		float rand_val = rand();
		float bounds = getMax() - getMin();
		return getMin() + (rand_val * bounds) / rand_max;
	}
// accessors
	float getMin() { return _min.get(); }
	float getMax() { return _max.get(); }
private:
// attributes
	BlockParam<float> _min;
	BlockParam<float> _max;
};

int __EXPORT blockRandUniformTest();

class __EXPORT BlockRandGauss: public Block
{
public:
// methods
	BlockRandGauss(SuperBlock *parent,
		       const char *name) :
		Block(parent, name),
		_mean(this, "MEAN"),
		_stdDev(this, "DEV") {
		// seed should be initialized somewhere
		// in main program for all calls to rand
		// XXX currently in nuttx if you seed to 0, rand breaks
	};
	virtual ~BlockRandGauss() {};
	float update() {
		static float V1, V2, S;
		static int phase = 0;
		float X;

		if (phase == 0) {
			do {
				float U1 = (float)rand() / MAX_RAND;
				float U2 = (float)rand() / MAX_RAND;
				V1 = 2 * U1 - 1;
				V2 = 2 * U2 - 1;
				S = V1 * V1 + V2 * V2;
			} while (S >= 1 || fabsf(S) < 1e-8f);

			X = V1 * float(sqrt(-2 * float(log(S)) / S));

		} else
			X = V2 * float(sqrt(-2 * float(log(S)) / S));

		phase = 1 - phase;
		return X * getStdDev() + getMean();
	}
// accessors
	float getMean() { return _mean.get(); }
	float getStdDev() { return _stdDev.get(); }
private:
// attributes
	BlockParam<float> _mean;
	BlockParam<float> _stdDev;
};

int __EXPORT blockRandGaussTest();

} // namespace control