lib/main/CMSIS/DSP/Source/ControllerFunctions/arm_pid_init_q31.c

   1 /* ----------------------------------------------------------------------
   2  * Project:      CMSIS DSP Library
   3  * Title:        arm_pid_init_q31.c
   4  * Description:  Q31 PID Control initialization function
   5  *
   6  * $Date:        27. January 2017
   7  * $Revision:    V.1.5.1
   8  *
   9  * Target Processor: Cortex-M cores
  10  * -------------------------------------------------------------------- */
  11 /*
  12  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
  13  *
  14  * SPDX-License-Identifier: Apache-2.0
  15  *
  16  * Licensed under the Apache License, Version 2.0 (the License); you may
  17  * not use this file except in compliance with the License.
  18  * You may obtain a copy of the License at
  19  *
  20  * www.apache.org/licenses/LICENSE-2.0
  21  *
  22  * Unless required by applicable law or agreed to in writing, software
  23  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  24  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  25  * See the License for the specific language governing permissions and
  26  * limitations under the License.
  27  */
  28
  29 #include "arm_math.h"
  30
  31  /**
  32  * @addtogroup PID
  33  * @{
  34  */
  35
  36 /**
  37  * @brief  Initialization function for the Q31 PID Control.
  38  * @param[in,out] *S points to an instance of the Q31 PID structure.
  39  * @param[in]     resetStateFlag  flag to reset the state. 0 = no change in state 1 = reset the state.
  40  * @return none.
  41  * \par Description:
  42  * \par
  43  * The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n
  44  * The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>
  45  * using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)
  46  * also sets the state variables to all zeros.
  47  */
  48
  49 void arm_pid_init_q31(
  50   arm_pid_instance_q31 * S,
  51   int32_t resetStateFlag)
  52 {
  53
  54 #if defined (ARM_MATH_DSP)
  55
  56   /* Run the below code for Cortex-M4 and Cortex-M3 */
  57
  58   /* Derived coefficient A0 */
  59   S->A0 = __QADD(__QADD(S->Kp, S->Ki), S->Kd);
  60
  61   /* Derived coefficient A1 */
  62   S->A1 = -__QADD(__QADD(S->Kd, S->Kd), S->Kp);
  63
  64
  65 #else
  66
  67   /* Run the below code for Cortex-M0 */
  68
  69   q31_t temp;
  70
  71   /* Derived coefficient A0 */
  72   temp = clip_q63_to_q31((q63_t) S->Kp + S->Ki);
  73   S->A0 = clip_q63_to_q31((q63_t) temp + S->Kd);
  74
  75   /* Derived coefficient A1 */
  76   temp = clip_q63_to_q31((q63_t) S->Kd + S->Kd);
  77   S->A1 = -clip_q63_to_q31((q63_t) temp + S->Kp);
  78
  79 #endif /* #if defined (ARM_MATH_DSP) */
  80
  81   /* Derived coefficient A2 */
  82   S->A2 = S->Kd;
  83
  84   /* Check whether state needs reset or not */
  85   if (resetStateFlag)
  86   {
  87     /* Clear the state buffer.  The size will be always 3 samples */
  88     memset(S->state, 0, 3U * sizeof(q31_t));
  89   }
  90
  91 }
  92
  93 /**
  94  * @} end of PID group
  95  */