arm_pid_init_q31.c

00001 /* ----------------------------------------------------------------------
00002  * Project:      CMSIS DSP Library
00003  * Title:        arm_pid_init_q31.c
00004  * Description:  Q31 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 Q31 PID Control.
00038  * @param[in,out] *S points to an instance of the Q31 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_q31(
00050   arm_pid_instance_q31 * S,
00051   int32_t resetStateFlag)
00052 {
00053 
00054 #if defined (ARM_MATH_DSP)
00055 
00056   /* Run the below code for Cortex-M4 and Cortex-M3 */
00057 
00058   /* Derived coefficient A0 */
00059   S->A0 = __QADD(__QADD(S->Kp, S->Ki), S->Kd);
00060 
00061   /* Derived coefficient A1 */
00062   S->A1 = -__QADD(__QADD(S->Kd, S->Kd), S->Kp);
00063 
00064 
00065 #else
00066 
00067   /* Run the below code for Cortex-M0 */
00068 
00069   q31_t temp;
00070 
00071   /* Derived coefficient A0 */
00072   temp = clip_q63_to_q31((q63_t) S->Kp + S->Ki);
00073   S->A0 = clip_q63_to_q31((q63_t) temp + S->Kd);
00074 
00075   /* Derived coefficient A1 */
00076   temp = clip_q63_to_q31((q63_t) S->Kd + S->Kd);
00077   S->A1 = -clip_q63_to_q31((q63_t) temp + S->Kp);
00078 
00079 #endif /* #if defined (ARM_MATH_DSP) */
00080 
00081   /* Derived coefficient A2 */
00082   S->A2 = S->Kd;
00083 
00084   /* Check whether state needs reset or not */
00085   if (resetStateFlag)
00086   {
00087     /* Clear the state buffer.  The size will be always 3 samples */
00088     memset(S->state, 0, 3U * sizeof(q31_t));
00089   }
00090 
00091 }
00092 
00093 /**
00094  * @} end of PID group
00095  */
00096