串级pid代码

下面是一个简单的串级PID控制的代码示例：

// 定义PID参数结构体
struct PIDParams {
  float kp;
  float ki;
  float kd;
  float integrator_max;
  float integrator_min;
};

// 定义PID控制器结构体
struct PIDController {
  PIDParams inner_params;
  PIDParams outer_params;
  float inner_error;
  float outer_error;
  float inner_integral;
  float outer_integral;
  float last_inner_error;
  float last_outer_error;
};

// 初始化PID控制器
void init_pid_controller(PIDController* controller, PIDParams inner_params, PIDParams outer_params) {
  controller->inner_params = inner_params;
  controller->outer_params = outer_params;
  controller->inner_error = 0;
  controller->outer_error = 0;
  controller->inner_integral = 0;
  controller->outer_integral = 0;
  controller->last_inner_error = 0;
  controller->last_outer_error = 0;
}

// 计算PID控制器的输出
float compute_pid_controller_output(PIDController* controller, float setpoint, float feedback) {
  // 计算内层PID控制器的输出
  controller->inner_error = setpoint - feedback;
  controller->inner_integral += controller->inner_error;
  if (controller->inner_integral > controller->inner_params.integrator_max) {
    controller->inner_integral = controller->inner_params.integrator_max;
  }
  if (controller->inner_integral < controller->inner_params.integrator_min) {
    controller->inner_integral = controller->inner_params.integrator_min;
  }
  float inner_derivative = controller->inner_error - controller->last_inner_error;
  float inner_output = controller->inner_params.kp * controller->inner_error +
                       controller->inner_params.ki * controller->inner_integral +
                       controller->inner_params.kd * inner_derivative;
  controller->last_inner_error = controller->inner_error;

  // 计算外层PID控制器的输出
  controller->outer_error = inner_output - feedback;
  controller->outer_integral += controller->outer_error;
  if (controller->outer_integral > controller->outer_params.integrator_max) {
    controller->outer_integral = controller->outer_params.integrator_max;
  }
  if (controller->outer_integral < controller->outer_params.integrator_min) {
    controller->outer_integral = controller->outer_params.integrator_min;
  }
  float outer_derivative = controller->outer_error - controller->last_outer_error;
  float outer_output = controller->outer_params.kp * controller->outer_error +
                       controller->outer_params.ki * controller->outer_integral +
                       controller->outer_params.kd * outer_derivative;
  controller->last_outer_error = controller->outer_error;

  // 返回PID控制器的输出
  return outer_output;
}

上述代码中，我们定义了一个PIDParams结构体，用于存储PID控制器的参数，包括比例系数kp、积分系数ki、微分系数kd以及积分上限和下限。我们还定义了一个PIDController结构体，用于存储PID控制器的状态，包括内层和外层PID控制器的参数、误差、积分项、上一次误差等。在初始化PID控制器时，我们需要设置内层和外层PID控制器的参数，并将其他状态变量初始化为0。在计算PID控制器的输出时，我们首先计算内层PID控制器的输出，然后将其作为外层PID控制器的输入，计算外层PID控制器的输出。最后，我们将外层PID控制器的输出作为整个PID控制器的输出，并将内层和外层PID控制器的状态变量保存下来，供下一次计算使用。