lib/main/CMSIS/DSP/Source/ControllerFunctions/arm_pid_init_f32.c

   1 /* ----------------------------------------------------------------------
   2  * Project:      CMSIS DSP Library
   3  * Title:        arm_pid_init_f32.c
   4  * Description:  Floating-point 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 floating-point PID Control.
  38  * @param[in,out] *S points to an instance of the 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_f32(
  50   arm_pid_instance_f32 * S,
  51   int32_t resetStateFlag)
  52 {
  53
  54   /* Derived coefficient A0 */
  55   S->A0 = S->Kp + S->Ki + S->Kd;
  56
  57   /* Derived coefficient A1 */
  58   S->A1 = (-S->Kp) - ((float32_t) 2.0 * S->Kd);
  59
  60   /* Derived coefficient A2 */
  61   S->A2 = S->Kd;
  62
  63   /* Check whether state needs reset or not */
  64   if (resetStateFlag)
  65   {
  66     /* Clear the state buffer.  The size will be always 3 samples */
  67     memset(S->state, 0, 3U * sizeof(float32_t));
  68   }
  69
  70 }
  71
  72 /**
  73  * @} end of PID group
  74  */