lib/main/CMSIS/DSP/Source/ControllerFunctions/arm_pid_init_q15.c

   1 /* ----------------------------------------------------------------------
   2  * Project:      CMSIS DSP Library
   3  * Title:        arm_pid_init_q15.c
   4  * Description:  Q15 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  * @details
  38  * @param[in,out] *S points to an instance of the Q15 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_q15(
  50   arm_pid_instance_q15 * 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 = __QADD16(__QADD16(S->Kp, S->Ki), S->Kd);
  60
  61   /* Derived coefficients and pack into A1 */
  62
  63 #ifndef  ARM_MATH_BIG_ENDIAN
  64
  65   S->A1 = __PKHBT(-__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), S->Kd, 16);
  66
  67 #else
  68
  69   S->A1 = __PKHBT(S->Kd, -__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), 16);
  70
  71 #endif /*      #ifndef  ARM_MATH_BIG_ENDIAN    */
  72
  73   /* Check whether state needs reset or not */
  74   if (resetStateFlag)
  75   {
  76     /* Clear the state buffer.  The size will be always 3 samples */
  77     memset(S->state, 0, 3U * sizeof(q15_t));
  78   }
  79
  80 #else
  81
  82   /* Run the below code for Cortex-M0 */
  83
  84   q31_t temp;                                    /*to store the sum */
  85
  86   /* Derived coefficient A0 */
  87   temp = S->Kp + S->Ki + S->Kd;
  88   S->A0 = (q15_t) __SSAT(temp, 16);
  89
  90   /* Derived coefficients and pack into A1 */
  91   temp = -(S->Kd + S->Kd + S->Kp);
  92   S->A1 = (q15_t) __SSAT(temp, 16);
  93   S->A2 = S->Kd;
  94
  95
  96
  97   /* Check whether state needs reset or not */
  98   if (resetStateFlag)
  99   {
 100     /* Clear the state buffer.  The size will be always 3 samples */
 101     memset(S->state, 0, 3U * sizeof(q15_t));
 102   }
 103
 104 #endif /* #if defined (ARM_MATH_DSP) */
 105
 106 }
 107
 108 /**
 109  * @} end of PID group
 110  */