用C语言写出anti_windup代码

Sure, here's an example code for implementing anti-windup in a simple control system using C language:

float prev_error = 0;
float integral = 0;
float Ki = 0.1; // integrator gain
float Kp = 0.5; // proportional gain
float setpoint = 50; // desired setpoint
float output = 0;
float max_output = 100; // saturation limit
float min_output = 0; // saturation limit

void control_loop(float input) {
    float error = setpoint - input;
    integral += error;
    if (integral > max_output/Ki) {
        integral = max_output/Ki;
    }
    else if (integral < min_output/Ki) {
        integral = min_output/Ki;
    }
    float derivative = error - prev_error;
    output = Kp*error + Ki*integral + Kd*derivative;
    if (output > max_output) {
        output = max_output;
        integral -= error;
    }
    else if (output < min_output) {
        output = min_output;
        integral -= error;
    }
    prev_error = error;
    // send output to actuator
}

In this code, the `integral` term is limited to prevent it from accumulating beyond the saturation limits. If the integral term exceeds the limit, it is set to the maximum or minimum value allowed by the limits. The output is also limited to the saturation limits, and if it exceeds the limits, the integral term is adjusted accordingly to prevent windup. This ensures that the control system remains stable and does not exceed any physical constraints.