PositionSensor.cpp

00001 
00002 #include "mbed.h"
00003 #include "PositionSensor.h"
00004 #include "../math_ops.h"
00005 //#include "offset_lut.h"
00006 //#include <math.h>
00007 
00008 PositionSensorAM5147::PositionSensorAM5147(int CPR, float offset, int ppairs){
00009     //_CPR = CPR;
00010     _CPR = CPR;
00011     _ppairs = ppairs;
00012     ElecOffset = offset;
00013     rotations = 0;
00014     spi = new SPI(PC_12, PC_11, PC_10);
00015     spi->format(16, 1);                                                          // mbed v>127 breaks 16-bit spi, so transaction is broken into 2 8-bit words
00016     spi->frequency(25000000);
00017     
00018     cs = new DigitalOut(PA_15);
00019     cs->write(1);
00020     readAngleCmd = 0xffff;   
00021     MechOffset = offset;
00022     modPosition = 0;
00023     oldModPosition = 0;
00024     oldVel = 0;
00025     raw = 0;
00026     }
00027     
00028 void PositionSensorAM5147::Sample(float dt){
00029     GPIOA->ODR &= ~(1 << 15);
00030     raw = spi->write(readAngleCmd);
00031     raw &= 0x3FFF;   
00032                                                           //Extract last 14 bits
00033     GPIOA->ODR |= (1 << 15);
00034     int off_1 = offset_lut[raw>>7];
00035     int off_2 = offset_lut[((raw>>7)+1)%128];
00036     int off_interp = off_1 + ((off_2 - off_1)*(raw - ((raw>>7)<<7))>>7);        // Interpolate between lookup table entries
00037     int angle = raw + off_interp;                                               // Correct for nonlinearity with lookup table from calibration
00038     if(angle - old_counts > _CPR/2){
00039         rotations -= 1;
00040         }
00041     else if (angle - old_counts < -_CPR/2){
00042         rotations += 1;
00043         }
00044     
00045     old_counts = angle;
00046     oldModPosition = modPosition;
00047     modPosition = ((2.0f*PI * ((float) angle))/ (float)_CPR);
00048     position = (2.0f*PI * ((float) angle+(_CPR*rotations)))/ (float)_CPR;
00049     MechPosition = position - MechOffset;
00050     float elec = ((2.0f*PI/(float)_CPR) * (float) ((_ppairs*angle)%_CPR)) + ElecOffset;
00051     if(elec < 0) elec += 2.0f*PI;
00052     else if(elec > 2.0f*PI) elec -= 2.0f*PI ; 
00053     ElecPosition = elec;
00054     
00055     float vel;
00056     //if(modPosition<.1f && oldModPosition>6.1f){
00057 
00058     if((modPosition-oldModPosition) < -3.0f){
00059         vel = (modPosition - oldModPosition + 2.0f*PI)/dt;
00060         }
00061     //else if(modPosition>6.1f && oldModPosition<0.1f){
00062     else if((modPosition - oldModPosition) > 3.0f){
00063         vel = (modPosition - oldModPosition - 2.0f*PI)/dt;
00064         }
00065     else{
00066         vel = (modPosition-oldModPosition)/dt;
00067     }    
00068     
00069     int n = 40;
00070     float sum = vel;
00071     for (int i = 1; i < (n); i++){
00072         velVec[n - i] = velVec[n-i-1];
00073         sum += velVec[n-i];
00074         }
00075     velVec[0] = vel;
00076     MechVelocity =  sum/((float)n);
00077     ElecVelocity = MechVelocity*_ppairs;
00078     ElecVelocityFilt = 0.99f*ElecVelocityFilt + 0.01f*ElecVelocity;
00079     }
00080 
00081 int PositionSensorAM5147::GetRawPosition(){
00082     return raw;
00083     }
00084 
00085 float PositionSensorAM5147::GetMechPositionFixed(){
00086     return MechPosition+MechOffset;
00087     }
00088     
00089 float PositionSensorAM5147::GetMechPosition(){
00090     return MechPosition;
00091     }
00092 
00093 float PositionSensorAM5147::GetElecPosition(){
00094     return ElecPosition;
00095     }
00096 
00097 float PositionSensorAM5147::GetElecVelocity(){
00098     return ElecVelocity;
00099     }
00100 
00101 float PositionSensorAM5147::GetMechVelocity(){
00102     return MechVelocity;
00103     }
00104 
00105 void PositionSensorAM5147::ZeroPosition(){
00106     rotations = 0;
00107     MechOffset = 0;
00108     Sample(.00025f);
00109     MechOffset = GetMechPosition();
00110     }
00111     
00112 void PositionSensorAM5147::SetElecOffset(float offset){
00113     ElecOffset = offset;
00114     }
00115 void PositionSensorAM5147::SetMechOffset(float offset){
00116     MechOffset = offset;
00117     }
00118 
00119 int PositionSensorAM5147::GetCPR(){
00120     return _CPR;
00121     }
00122 
00123 
00124 void PositionSensorAM5147::WriteLUT(int new_lut[128]){
00125     memcpy(offset_lut, new_lut, sizeof(offset_lut));
00126     }
00127     
00128 
00129 
00130 PositionSensorEncoder::PositionSensorEncoder(int CPR, float offset, int ppairs) {
00131     _ppairs = ppairs;
00132     _CPR = CPR;
00133     _offset = offset;
00134     MechPosition = 0;
00135     out_old = 0;
00136     oldVel = 0;
00137     raw = 0;
00138     
00139     // Enable clock for GPIOA
00140     __GPIOA_CLK_ENABLE(); //equivalent from hal_rcc.h
00141  
00142     GPIOA->MODER   |= GPIO_MODER_MODER6_1 | GPIO_MODER_MODER7_1 ;           //PA6 & PA7 as Alternate Function   /*!< GPIO port mode register,               Address offset: 0x00      */
00143     GPIOA->OTYPER  |= GPIO_OTYPER_OT_6 | GPIO_OTYPER_OT_7 ;                 //PA6 & PA7 as Inputs               /*!< GPIO port output type register,        Address offset: 0x04      */
00144     GPIOA->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR6 | GPIO_OSPEEDER_OSPEEDR7 ;     //Low speed                         /*!< GPIO port output speed register,       Address offset: 0x08      */
00145     GPIOA->PUPDR   |= GPIO_PUPDR_PUPDR6_1 | GPIO_PUPDR_PUPDR7_1 ;           //Pull Down                         /*!< GPIO port pull-up/pull-down register,  Address offset: 0x0C      */
00146     GPIOA->AFR[0]  |= 0x22000000 ;                                          //AF02 for PA6 & PA7                /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
00147     GPIOA->AFR[1]  |= 0x00000000 ;                                          //nibbles here refer to gpio8..15   /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
00148    
00149     // configure TIM3 as Encoder input
00150     // Enable clock for TIM3
00151     __TIM3_CLK_ENABLE();
00152  
00153     TIM3->CR1   = 0x0001;                                                   // CEN(Counter ENable)='1'     < TIM control register 1
00154     TIM3->SMCR  = TIM_ENCODERMODE_TI12;                                     // SMS='011' (Encoder mode 3)  < TIM slave mode control register
00155     TIM3->CCMR1 = 0x1111;                                                   // CC1S='01' CC2S='01'         < TIM capture/compare mode register 1, maximum digital filtering
00156     TIM3->CCMR2 = 0x0000;                                                   //                             < TIM capture/compare mode register 2
00157     TIM3->CCER  = 0x0011;                                                   // CC1P CC2P                   < TIM capture/compare enable register
00158     TIM3->PSC   = 0x0000;                                                   // Prescaler = (0+1)           < TIM prescaler
00159     TIM3->ARR   = CPR;                                                      // IM auto-reload register
00160   
00161     TIM3->CNT = 0x000;  //reset the counter before we use it  
00162     
00163     // Extra Timer for velocity measurement
00164     
00165     __TIM2_CLK_ENABLE();
00166     TIM3->CR2 = 0x030;                                                      //MMS = 101
00167     
00168     TIM2->PSC = 0x03;
00169     //TIM2->CR2 |= TIM_CR2_TI1S;
00170     TIM2->SMCR = 0x24;                                                      //TS = 010 for ITR2, SMS = 100 (reset counter at edge)
00171     TIM2->CCMR1 = 0x3;                                                      // CC1S = 11, IC1 mapped on TRC
00172     
00173     //TIM2->CR2 |= TIM_CR2_TI1S;
00174     TIM2->CCER |= TIM_CCER_CC1P;
00175     //TIM2->CCER |= TIM_CCER_CC1NP;
00176     TIM2->CCER |= TIM_CCER_CC1E;
00177     
00178     
00179     TIM2->CR1 = 0x01;                                                       //CEN,  enable timer
00180     
00181     TIM3->CR1   = 0x01;                                                     // CEN
00182     ZPulse = new InterruptIn(PC_4);
00183     ZSense = new DigitalIn(PC_4);
00184     //ZPulse = new InterruptIn(PB_0);
00185     //ZSense = new DigitalIn(PB_0);
00186     ZPulse->enable_irq();
00187     ZPulse->rise(this, &PositionSensorEncoder::ZeroEncoderCount);
00188     //ZPulse->fall(this, &PositionSensorEncoder::ZeroEncoderCountDown);
00189     ZPulse->mode(PullDown);
00190     flag = 0;
00191 
00192     
00193     //ZTest = new DigitalOut(PC_2);
00194     //ZTest->write(1);
00195     }
00196     
00197 void PositionSensorEncoder::Sample(float dt){
00198     
00199     }
00200 
00201  
00202 float PositionSensorEncoder::GetMechPosition() {                            //returns rotor angle in radians.
00203     int raw = TIM3->CNT;
00204     float unsigned_mech = (6.28318530718f/(float)_CPR) * (float) ((raw)%_CPR);
00205     return (float) unsigned_mech;// + 6.28318530718f* (float) rotations;
00206 }
00207 
00208 float PositionSensorEncoder::GetElecPosition() {                            //returns rotor electrical angle in radians.
00209     int raw = TIM3->CNT;
00210     float elec = ((6.28318530718f/(float)_CPR) * (float) ((_ppairs*raw)%_CPR)) - _offset;
00211     if(elec < 0) elec += 6.28318530718f;
00212     return elec;
00213 }
00214 
00215 
00216     
00217 float PositionSensorEncoder::GetMechVelocity(){
00218 
00219     float out = 0;
00220     float rawPeriod = TIM2->CCR1; //Clock Ticks
00221     int currentTime = TIM2->CNT;
00222     if(currentTime > 2000000){rawPeriod = currentTime;}
00223     float  dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f;    // +/- 1
00224     float meas = dir*180000000.0f*(6.28318530718f/(float)_CPR)/rawPeriod; 
00225     if(isinf(meas)){ meas = 1;}
00226     out = meas;
00227     //if(meas == oldVel){
00228      //   out = .9f*out_old;
00229      //   }
00230     
00231  
00232     oldVel = meas;
00233     out_old = out;
00234     int n = 16;
00235     float sum = out;
00236     for (int i = 1; i < (n); i++){
00237         velVec[n - i] = velVec[n-i-1];
00238         sum += velVec[n-i];
00239         }
00240     velVec[0] = out;
00241     return sum/(float)n;
00242     }
00243     
00244 float PositionSensorEncoder::GetElecVelocity(){
00245     return _ppairs*GetMechVelocity();
00246     }
00247     
00248 void PositionSensorEncoder::ZeroEncoderCount(void){
00249     if (ZSense->read() == 1 & flag == 0){
00250         if (ZSense->read() == 1){
00251             GPIOC->ODR ^= (1 << 4);   
00252             TIM3->CNT = 0x000;
00253             //state = !state;
00254             //ZTest->write(state);
00255             GPIOC->ODR ^= (1 << 4);
00256             //flag = 1;
00257         }
00258         }
00259     }
00260 
00261 void PositionSensorEncoder::ZeroPosition(void){
00262     
00263     }
00264     
00265 void PositionSensorEncoder::ZeroEncoderCountDown(void){
00266     if (ZSense->read() == 0){
00267         if (ZSense->read() == 0){
00268             GPIOC->ODR ^= (1 << 4);
00269             flag = 0;
00270             float dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f;
00271             if(dir != dir){
00272                 dir = dir;
00273                 rotations +=  dir;
00274                 }
00275 
00276             GPIOC->ODR ^= (1 << 4);
00277 
00278         }
00279         }
00280     }
00281 void PositionSensorEncoder::SetElecOffset(float offset){
00282     
00283     }
00284     
00285 int PositionSensorEncoder::GetRawPosition(void){
00286     return 0;
00287     }
00288     
00289 int PositionSensorEncoder::GetCPR(){
00290     return _CPR;
00291     }
00292     
00293 
00294 void PositionSensorEncoder::WriteLUT(int new_lut[128]){
00295     memcpy(offset_lut, new_lut, sizeof(offset_lut));
00296     }