tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ControllerFunctions/arm_pid_init_f32.c

   1 /* ----------------------------------------------------------------------
   2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
   3 *
   4 * $Date:        17. January 2013
   5 * $Revision:    V1.4.1
   6 *
   7 * Project:          CMSIS DSP Library
   8 * Title:            arm_pid_init_f32.c
   9 *
  10 * Description:  Floating-point PID Control initialization function
  11 *
  12 *
  13 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  14 *
  15 * Redistribution and use in source and binary forms, with or without
  16 * modification, are permitted provided that the following conditions
  17 * are met:
  18 *   - Redistributions of source code must retain the above copyright
  19 *     notice, this list of conditions and the following disclaimer.
  20 *   - Redistributions in binary form must reproduce the above copyright
  21 *     notice, this list of conditions and the following disclaimer in
  22 *     the documentation and/or other materials provided with the
  23 *     distribution.
  24 *   - Neither the name of ARM LIMITED nor the names of its contributors
  25 *     may be used to endorse or promote products derived from this
  26 *     software without specific prior written permission.
  27 *
  28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  31 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  32 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  33 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  34 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  35 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  36 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  38 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  39 * POSSIBILITY OF SUCH DAMAGE.
  40 * ------------------------------------------------------------------- */
  41
  42 #include "arm_math.h"
  43
  44  /**
  45  * @addtogroup PID
  46  * @{
  47  */
  48
  49 /**
  50  * @brief  Initialization function for the floating-point PID Control.
  51  * @param[in,out] *S points to an instance of the PID structure.
  52  * @param[in]     resetStateFlag  flag to reset the state. 0 = no change in state & 1 = reset the state.
  53  * @return none.
  54  * \par Description:
  55  * \par
  56  * The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n
  57  * The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>
  58  * using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)
  59  * also sets the state variables to all zeros.
  60  */
  61
  62 void arm_pid_init_f32(
  63   arm_pid_instance_f32 * S,
  64   int32_t resetStateFlag)
  65 {
  66
  67   /* Derived coefficient A0 */
  68   S->A0 = S->Kp + S->Ki + S->Kd;
  69
  70   /* Derived coefficient A1 */
  71   S->A1 = (-S->Kp) - ((float32_t) 2.0 * S->Kd);
  72
  73   /* Derived coefficient A2 */
  74   S->A2 = S->Kd;
  75
  76   /* Check whether state needs reset or not */
  77   if(resetStateFlag)
  78   {
  79     /* Clear the state buffer.  The size will be always 3 samples */
  80     memset(S->state, 0, 3u * sizeof(float32_t));
  81   }
  82
  83 }
  84
  85 /**
  86  * @} end of PID group
  87  */