arm_pid_init_f32.c

00001 /* ----------------------------------------------------------------------  
00002 * Copyright (C) 2010 ARM Limited. All rights reserved.  
00003 *  
00004 * $Date:        29. November 2010  
00005 * $Revision:    V1.0.3  
00006 *  
00007 * Project:      CMSIS DSP Library  
00008 * Title:        arm_pid_init_f32.c  
00009 *  
00010 * Description:  Floating-point PID Control initialization function  
00011 *                
00012 *  
00013 * Target Processor: Cortex-M4/Cortex-M3
00014 *  
00015 * Version 1.0.3 2010/11/29 
00016 *    Re-organized the CMSIS folders and updated documentation.  
00017 *   
00018 * Version 1.0.2 2010/11/11  
00019 *    Documentation updated.   
00020 *  
00021 * Version 1.0.1 2010/10/05   
00022 *    Production release and review comments incorporated.  
00023 *  
00024 * Version 1.0.0 2010/09/20   
00025 *    Production release and review comments incorporated.  
00026 * ------------------------------------------------------------------- */ 
00027  
00028 #include "arm_math.h" 
00029  
00030  /**  
00031  * @addtogroup PID  
00032  * @{  
00033  */ 
00034  
00035 /**  
00036  * @brief  Initialization function for the floating-point PID Control. 
00037  * @param[in,out] *S points to an instance of the PID structure. 
00038  * @param[in]     resetStateFlag  flag to reset the state. 0 = no change in state & 1 = reset the state. 
00039  * @return none. 
00040  * \par Description: 
00041  * \par  
00042  * The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n 
00043  * The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>  
00044  * using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)  
00045  * also sets the state variables to all zeros.  
00046  */  
00047   
00048 void arm_pid_init_f32(  
00049   arm_pid_instance_f32 * S,  
00050   int32_t resetStateFlag) 
00051 {  
00052   
00053   /* Derived coefficient A0 */  
00054   S->A0 = S->Kp + S->Ki + S->Kd;  
00055   
00056   /* Derived coefficient A1 */  
00057   S->A1 = (-S->Kp) - ((float32_t) 2.0 * S->Kd);  
00058   
00059   /* Derived coefficient A2 */  
00060   S->A2 = S->Kd;  
00061   
00062   /* Check whether state needs reset or not */  
00063   if(resetStateFlag) 
00064   {  
00065     /* Clear the state buffer.  The size will be always 3 samples */  
00066     memset(S->state, 0, 3u * sizeof(float32_t));  
00067   }  
00068   
00069 }  
00070   
00071 /**  
00072  * @} end of PID group  
00073  */