| /* ---------------------------------------------------------------------- |
| * Project: CMSIS DSP Library |
| * Title: arm_pid_init_q15.c |
| * Description: Q15 PID Control initialization function |
| * |
| * $Date: 18. March 2019 |
| * $Revision: V1.6.0 |
| * |
| * Target Processor: Cortex-M cores |
| * -------------------------------------------------------------------- */ |
| /* |
| * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the License); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an AS IS BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "arm_math.h" |
| |
| /** |
| @addtogroup PID |
| @{ |
| */ |
| |
| /** |
| @brief Initialization function for the Q15 PID Control. |
| @param[in,out] S points to an instance of the Q15 PID structure |
| @param[in] resetStateFlag |
| - value = 0: no change in state |
| - value = 1: reset state |
| @return none |
| |
| @par Details |
| The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n |
| The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code> |
| using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd) |
| also sets the state variables to all zeros. |
| */ |
| |
| void arm_pid_init_q15( |
| arm_pid_instance_q15 * S, |
| int32_t resetStateFlag) |
| { |
| |
| #if defined (ARM_MATH_DSP) |
| |
| /* Derived coefficient A0 */ |
| S->A0 = __QADD16(__QADD16(S->Kp, S->Ki), S->Kd); |
| |
| /* Derived coefficients and pack into A1 */ |
| |
| #ifndef ARM_MATH_BIG_ENDIAN |
| S->A1 = __PKHBT(-__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), S->Kd, 16); |
| #else |
| S->A1 = __PKHBT(S->Kd, -__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), 16); |
| #endif |
| |
| #else |
| |
| q31_t temp; /* to store the sum */ |
| |
| /* Derived coefficient A0 */ |
| temp = S->Kp + S->Ki + S->Kd; |
| S->A0 = (q15_t) __SSAT(temp, 16); |
| |
| /* Derived coefficients and pack into A1 */ |
| temp = -(S->Kd + S->Kd + S->Kp); |
| S->A1 = (q15_t) __SSAT(temp, 16); |
| S->A2 = S->Kd; |
| |
| #endif /* #if defined (ARM_MATH_DSP) */ |
| |
| /* Check whether state needs reset or not */ |
| if (resetStateFlag) |
| { |
| /* Reset state to zero, The size will be always 3 samples */ |
| memset(S->state, 0, 3U * sizeof(q15_t)); |
| } |
| |
| } |
| |
| /** |
| @} end of PID group |
| */ |