arm_pid_init_f32.c

00001 /* ----------------------------------------------------------------------
00002  * Project:      CMSIS DSP Library
00003  * Title:        arm_pid_init_f32.c
00004  * Description:  Floating-point PID Control initialization function
00005  *
00006  * $Date:        27. January 2017
00007  * $Revision:    V.1.5.1
00008  *
00009  * Target Processor: Cortex-M cores
00010  * -------------------------------------------------------------------- */
00011 /*
00012  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
00013  *
00014  * SPDX-License-Identifier: Apache-2.0
00015  *
00016  * Licensed under the Apache License, Version 2.0 (the License); you may
00017  * not use this file except in compliance with the License.
00018  * You may obtain a copy of the License at
00019  *
00020  * www.apache.org/licenses/LICENSE-2.0
00021  *
00022  * Unless required by applicable law or agreed to in writing, software
00023  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00024  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00025  * See the License for the specific language governing permissions and
00026  * limitations under the License.
00027  */
00028 
00029 #include "arm_math.h"
00030 
00031  /**
00032  * @addtogroup PID
00033  * @{
00034  */
00035 
00036 /**
00037  * @brief  Initialization function for the floating-point PID Control.
00038  * @param[in,out] *S points to an instance of the PID structure.
00039  * @param[in]     resetStateFlag  flag to reset the state. 0 = no change in state & 1 = reset the state.
00040  * @return none.
00041  * \par Description:
00042  * \par
00043  * The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n
00044  * The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>
00045  * using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)
00046  * also sets the state variables to all zeros.
00047  */
00048 
00049 void arm_pid_init_f32(
00050   arm_pid_instance_f32 * S,
00051   int32_t resetStateFlag)
00052 {
00053 
00054   /* Derived coefficient A0 */
00055   S->A0 = S->Kp + S->Ki + S->Kd;
00056 
00057   /* Derived coefficient A1 */
00058   S->A1 = (-S->Kp) - ((float32_t) 2.0 * S->Kd);
00059 
00060   /* Derived coefficient A2 */
00061   S->A2 = S->Kd;
00062 
00063   /* Check whether state needs reset or not */
00064   if (resetStateFlag)
00065   {
00066     /* Clear the state buffer.  The size will be always 3 samples */
00067     memset(S->state, 0, 3U * sizeof(float32_t));
00068   }
00069 
00070 }
00071 
00072 /**
00073  * @} end of PID group
00074  */
00075