例如void arm_pid_init_f32(
  arm_pid_instance_f32 * S,
  int32_t resetStateFlag)
{

  /* Derived coefficient A0 */
  S->A0 = S->Kp + S->Ki + S->Kd;

  /* Derived coefficient A1 */
  S->A1 = (-S->Kp) - ((float32_t) 2.0 * S->Kd);

  /* Derived coefficient A2 */
  S->A2 = S->Kd;

  /* Check whether state needs reset or not */
  if(resetStateFlag)
  {
    /* Clear the state buffer.  The size will be always 3 samples */
    memset(S->state, 0, 3u * sizeof(float32_t));
  }

}

typedef struct
  {
    q31_t A0;            /**< The derived gain, A0 = Kp + Ki + Kd . */
    q31_t A1;            /**< The derived gain, A1 = -Kp - 2Kd. */
    q31_t A2;            /**< The derived gain, A2 = Kd . */
    q31_t state[3];      /**< The state array of length 3. */
    q31_t Kp;            /**< The proportional gain. */
    q31_t Ki;            /**< The integral gain. */
    q31_t Kd;            /**< The derivative gain. */
  } arm_pid_instance_q31;