鉴于控制算法常于嵌入式平台使用，所以使用C语言实现模糊PID控制算法。实现的功能包括但不限于：
- 隶属度函数 Membership function
- 高斯隶属度函数 Gaussian membership function
- 广义钟形隶属度函数 Generalized bell-shaped membership function
- S形隶属度函数 Sigmoidal membership function
- 梯形隶属度函数 Trapezoidal membership function
- 三角形隶属度函数 Triangular membership function
- Z形隶属度函数 Z-shaped membership function
- 模糊算子 Fuzzy operator
- 并算子 Union operator
- 交算子 Intersection operator
- 平衡算子 Equilibrium operator
- 中心平均解模糊器 Mean of centers defuzzifier
API使用的示例代码如下：
#include "fuzzyPID.h"
#define DOF 6
int main() {
// Default fuzzy rule base of delta kp/ki/kd
int rule_base[][qf_default] = {
//delta kp rule base
{PB, PB, PM, PM, PS, ZO, ZO},
{PB, PB, PM, PS, PS, ZO, NS},
{PM, PM, PM, PS, ZO, NS, NS},
{PM, PM, PS, ZO, NS, NM, NM},
{PS, PS, ZO, NS, NS, NM, NM},
{PS, ZO, NS, NM, NM, NM, NB},
{ZO, ZO, NM, NM, NM, NB, NB},
//delta ki rule base
{NB, NB, NM, NM, NS, ZO, ZO},
{NB, NB, NM, NS, NS, ZO, ZO},
{NB, NM, NS, NS, ZO, PS, PS},
{NM, NM, NS, ZO, PS, PM, PM},
{NM, NS, ZO, PS, PS, PM, PB},
{ZO, ZO, PS, PS, PM, PB, PB},
{ZO, ZO, PS, PM, PM, PB, PB},
//delta kd rule base
{PS, NS, NB, NB, NB, NM, PS},
{PS, NS, NB, NM, NM, NS, ZO},
{ZO, NS, NM, NM, NS, NS, ZO},
{ZO, NS, NS, NS, NS, NS, ZO},
{ZO, ZO, ZO, ZO, ZO, ZO, ZO},
{PB, PS, PS, PS, PS, PS, PB},
{PB, PM, PM, PM, PS, PS, PB}};
// Default parameters of membership function
int mf_params[4 * qf_default] = {-3, -3, -2, 0,
-3, -2, -1, 0,
-2, -1, 0, 0,
-1, 0, 1, 0,
0, 1, 2, 0,
1, 2, 3, 0,
2, 3, 3, 0};
// Default parameters of pid controller
float fuzzy_pid_params[DOF][pid_params_count] = {{0.65f, 0, 0, 0, 0, 0, 1},
{-0.34f, 0, 0, 0, 0, 0, 1},
{-1.1f, 0, 0, 0, 0, 0, 1},
{-2.4f, 0, 0, 0, 0, 0, 1},
{1.2f, 0, 0, 0, 0, 0, 1},
{1.2f, 0.05f, 0.1f, 0, 0, 0, 1}};
// Obtain the PID controller vector according to the parameters
struct PID **pid_vector = fuzzy_pid_vector_init(fuzzy_pid_params, 2.0f, 4, 1, 0, mf_params, rule_base, DOF);
printf("output:\n");
int control_id = 5;
float real = 0;
float idea = max_error * 0.9f;
printf("idea value: %f\n", idea);
bool direct[DOF] = {true, false, false, false, true, true};
for (int j = 0; j < 1000; ++j) {
int out = fuzzy_pid_motor_pwd_output(real, idea, direct[control_id], pid_vector[control_id]);
real += (float) (out - middle_pwm_output) / (float) middle_pwm_output * (float) max_error * 0.1f;
printf("%d,%f\n", out, real);
}
delete_pid_vector(pid_vector, DOF);
return 0;
}