1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_pid_init_q31.c
4 * Description: Q31 PID Control initialization function
5 *
6 * $Date: 23 April 2021
7 * $Revision: V1.9.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2021 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 "dsp/controller_functions.h"
30
31 /**
32 @addtogroup PID
33 @{
34 */
35
36 /**
37 @brief Initialization function for the Q31 PID Control.
38 @param[in,out] S points to an instance of the Q31 PID structure
39 @param[in] resetStateFlag
40 - value = 0: no change in state
41 - value = 1: reset state
42
43 @par Details
44 The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n
45 The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>
46 using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)
47 also sets the state variables to all zeros.
48 */
49
arm_pid_init_q31(arm_pid_instance_q31 * S,int32_t resetStateFlag)50 void arm_pid_init_q31(
51 arm_pid_instance_q31 * S,
52 int32_t resetStateFlag)
53 {
54
55 #if defined (ARM_MATH_DSP)
56
57 /* Derived coefficient A0 */
58 S->A0 = __QADD(__QADD(S->Kp, S->Ki), S->Kd);
59
60 /* Derived coefficient A1 */
61 S->A1 = -__QADD(__QADD(S->Kd, S->Kd), S->Kp);
62
63 #else
64
65 q31_t temp; /* to store the sum */
66
67 /* Derived coefficient A0 */
68 temp = clip_q63_to_q31((q63_t) S->Kp + S->Ki);
69 S->A0 = clip_q63_to_q31((q63_t) temp + S->Kd);
70
71 /* Derived coefficient A1 */
72 temp = clip_q63_to_q31((q63_t) S->Kd + S->Kd);
73 S->A1 = -clip_q63_to_q31((q63_t) temp + S->Kp);
74
75 #endif /* #if defined (ARM_MATH_DSP) */
76
77 /* Derived coefficient A2 */
78 S->A2 = S->Kd;
79
80 /* Check whether state needs reset or not */
81 if (resetStateFlag)
82 {
83 /* Reset state to zero, The size will be always 3 samples */
84 memset(S->state, 0, 3U * sizeof(q31_t));
85 }
86
87 }
88
89 /**
90 @} end of PID group
91 */
92
