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     first_sample = 0;
00027     for(int i = 0; i<100; i++)              // Initial measurement is really noisy
00028     {
00029         spi->write(0);
00030         wait_us(100);
00031     }
00032 
00033     }
00034     
00035 void PositionSensorAM5147::Sample(float dt){
00036     GPIOA->ODR &= ~(1 << 15);
00037     //raw = spi->write(readAngleCmd);
00038     //raw &= 0x3FFF;   
00039     raw = spi->write(0);
00040     raw = raw>>2;                                                             //Extract last 14 bits
00041     GPIOA->ODR |= (1 << 15);
00042     int off_1 = offset_lut[raw>>7];
00043     int off_2 = offset_lut[((raw>>7)+1)%128];
00044     int off_interp = off_1 + ((off_2 - off_1)*(raw - ((raw>>7)<<7))>>7);        // Interpolate between lookup table entries
00045     int angle = raw + off_interp;                                               // Correct for nonlinearity with lookup table from calibration
00046     
00047     if(first_sample){
00048         if(angle - old_counts > _CPR/2){
00049             rotations -= 1;
00050             }
00051         else if (angle - old_counts < -_CPR/2){
00052             rotations += 1;
00053             }
00054     }
00055     if(!first_sample){first_sample = 1;}
00056     
00057     old_counts = angle;
00058     oldModPosition = modPosition;
00059     modPosition = ((2.0f*PI * ((float) angle))/ (float)_CPR);
00060     position = (2.0f*PI * ((float) angle+(_CPR*rotations)))/ (float)_CPR;
00061     MechPosition = position - MechOffset;
00062     float elec = ((2.0f*PI/(float)_CPR) * (float) ((_ppairs*angle)%_CPR)) + ElecOffset;
00063     if(elec < 0) elec += 2.0f*PI;
00064     else if(elec > 2.0f*PI) elec -= 2.0f*PI ; 
00065     ElecPosition = elec;
00066     
00067     float vel;
00068     //if(modPosition<.1f && oldModPosition>6.1f){
00069 
00070     if((modPosition-oldModPosition) < -3.0f){
00071         vel = (modPosition - oldModPosition + 2.0f*PI)/dt;
00072         }
00073     //else if(modPosition>6.1f && oldModPosition<0.1f){
00074     else if((modPosition - oldModPosition) > 3.0f){
00075         vel = (modPosition - oldModPosition - 2.0f*PI)/dt;
00076         }
00077     else{
00078         vel = (modPosition-oldModPosition)/dt;
00079     }    
00080     
00081     int n = 40;
00082     float sum = vel;
00083     for (int i = 1; i < (n); i++){
00084         velVec[n - i] = velVec[n-i-1];
00085         sum += velVec[n-i];
00086         }
00087     velVec[0] = vel;
00088     MechVelocity =  sum/((float)n);
00089     ElecVelocity = MechVelocity*_ppairs;
00090     ElecVelocityFilt = 0.99f*ElecVelocityFilt + 0.01f*ElecVelocity;
00091     }
00092 
00093 int PositionSensorAM5147::GetRawPosition(){
00094     return raw;
00095     }
00096 
00097 float PositionSensorAM5147::GetMechPositionFixed(){
00098     return MechPosition+MechOffset;
00099     }
00100     
00101 float PositionSensorAM5147::GetMechPosition(){
00102     return MechPosition;
00103     }
00104 
00105 float PositionSensorAM5147::GetElecPosition(){
00106     return ElecPosition;
00107     }
00108 
00109 float PositionSensorAM5147::GetElecVelocity(){
00110     return ElecVelocity;
00111     }
00112 
00113 float PositionSensorAM5147::GetMechVelocity(){
00114     return MechVelocity;
00115     }
00116 
00117 void PositionSensorAM5147::ZeroPosition(){
00118     rotations = 0;
00119     MechOffset = 0;
00120     Sample(.00025f);
00121     MechOffset = GetMechPosition();
00122     }
00123     
00124 void PositionSensorAM5147::SetElecOffset(float offset){
00125     ElecOffset = offset;
00126     }
00127 void PositionSensorAM5147::SetMechOffset(float offset){
00128     MechOffset = offset;
00129     first_sample = 0;
00130     }
00131 
00132 int PositionSensorAM5147::GetCPR(){
00133     return _CPR;
00134     }
00135 
00136 
00137 void PositionSensorAM5147::WriteLUT(int new_lut[128]){
00138     memcpy(offset_lut, new_lut, sizeof(offset_lut));
00139     }
00140     
00141 
00142 
00143 PositionSensorEncoder::PositionSensorEncoder(int CPR, float offset, int ppairs) {
00144     _ppairs = ppairs;
00145     _CPR = CPR;
00146     _offset = offset;
00147     MechPosition = 0;
00148     out_old = 0;
00149     oldVel = 0;
00150     raw = 0;
00151     
00152     // Enable clock for GPIOA
00153     __GPIOA_CLK_ENABLE(); //equivalent from hal_rcc.h
00154  
00155     GPIOA->MODER   |= GPIO_MODER_MODER6_1 | GPIO_MODER_MODER7_1 ;           //PA6 & PA7 as Alternate Function   /*!< GPIO port mode register,               Address offset: 0x00      */
00156     GPIOA->OTYPER  |= GPIO_OTYPER_OT_6 | GPIO_OTYPER_OT_7 ;                 //PA6 & PA7 as Inputs               /*!< GPIO port output type register,        Address offset: 0x04      */
00157     GPIOA->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR6 | GPIO_OSPEEDER_OSPEEDR7 ;     //Low speed                         /*!< GPIO port output speed register,       Address offset: 0x08      */
00158     GPIOA->PUPDR   |= GPIO_PUPDR_PUPDR6_1 | GPIO_PUPDR_PUPDR7_1 ;           //Pull Down                         /*!< GPIO port pull-up/pull-down register,  Address offset: 0x0C      */
00159     GPIOA->AFR[0]  |= 0x22000000 ;                                          //AF02 for PA6 & PA7                /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
00160     GPIOA->AFR[1]  |= 0x00000000 ;                                          //nibbles here refer to gpio8..15   /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
00161    
00162     // configure TIM3 as Encoder input
00163     // Enable clock for TIM3
00164     __TIM3_CLK_ENABLE();
00165  
00166     TIM3->CR1   = 0x0001;                                                   // CEN(Counter ENable)='1'     < TIM control register 1
00167     TIM3->SMCR  = TIM_ENCODERMODE_TI12;                                     // SMS='011' (Encoder mode 3)  < TIM slave mode control register
00168     TIM3->CCMR1 = 0x1111;                                                   // CC1S='01' CC2S='01'         < TIM capture/compare mode register 1, maximum digital filtering
00169     TIM3->CCMR2 = 0x0000;                                                   //                             < TIM capture/compare mode register 2
00170     TIM3->CCER  = 0x0011;                                                   // CC1P CC2P                   < TIM capture/compare enable register
00171     TIM3->PSC   = 0x0000;                                                   // Prescaler = (0+1)           < TIM prescaler
00172     TIM3->ARR   = CPR;                                                      // IM auto-reload register
00173   
00174     TIM3->CNT = 0x000;  //reset the counter before we use it  
00175     
00176     // Extra Timer for velocity measurement
00177     
00178     __TIM2_CLK_ENABLE();
00179     TIM3->CR2 = 0x030;                                                      //MMS = 101
00180     
00181     TIM2->PSC = 0x03;
00182     //TIM2->CR2 |= TIM_CR2_TI1S;
00183     TIM2->SMCR = 0x24;                                                      //TS = 010 for ITR2, SMS = 100 (reset counter at edge)
00184     TIM2->CCMR1 = 0x3;                                                      // CC1S = 11, IC1 mapped on TRC
00185     
00186     //TIM2->CR2 |= TIM_CR2_TI1S;
00187     TIM2->CCER |= TIM_CCER_CC1P;
00188     //TIM2->CCER |= TIM_CCER_CC1NP;
00189     TIM2->CCER |= TIM_CCER_CC1E;
00190     
00191     
00192     TIM2->CR1 = 0x01;                                                       //CEN,  enable timer
00193     
00194     TIM3->CR1   = 0x01;                                                     // CEN
00195     ZPulse = new InterruptIn(PC_4);
00196     ZSense = new DigitalIn(PC_4);
00197     //ZPulse = new InterruptIn(PB_0);
00198     //ZSense = new DigitalIn(PB_0);
00199     ZPulse->enable_irq();
00200     ZPulse->rise(this, &PositionSensorEncoder::ZeroEncoderCount);
00201     //ZPulse->fall(this, &PositionSensorEncoder::ZeroEncoderCountDown);
00202     ZPulse->mode(PullDown);
00203     flag = 0;
00204 
00205     
00206     //ZTest = new DigitalOut(PC_2);
00207     //ZTest->write(1);
00208     }
00209     
00210 void PositionSensorEncoder::Sample(float dt){
00211     
00212     }
00213 
00214  
00215 float PositionSensorEncoder::GetMechPosition() {                            //returns rotor angle in radians.
00216     int raw = TIM3->CNT;
00217     float unsigned_mech = (6.28318530718f/(float)_CPR) * (float) ((raw)%_CPR);
00218     return (float) unsigned_mech;// + 6.28318530718f* (float) rotations;
00219 }
00220 
00221 float PositionSensorEncoder::GetElecPosition() {                            //returns rotor electrical angle in radians.
00222     int raw = TIM3->CNT;
00223     float elec = ((6.28318530718f/(float)_CPR) * (float) ((_ppairs*raw)%_CPR)) - _offset;
00224     if(elec < 0) elec += 6.28318530718f;
00225     return elec;
00226 }
00227 
00228 
00229     
00230 float PositionSensorEncoder::GetMechVelocity(){
00231 
00232     float out = 0;
00233     float rawPeriod = TIM2->CCR1; //Clock Ticks
00234     int currentTime = TIM2->CNT;
00235     if(currentTime > 2000000){rawPeriod = currentTime;}
00236     float  dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f;    // +/- 1
00237     float meas = dir*180000000.0f*(6.28318530718f/(float)_CPR)/rawPeriod; 
00238     if(isinf(meas)){ meas = 1;}
00239     out = meas;
00240     //if(meas == oldVel){
00241      //   out = .9f*out_old;
00242      //   }
00243     
00244  
00245     oldVel = meas;
00246     out_old = out;
00247     int n = 16;
00248     float sum = out;
00249     for (int i = 1; i < (n); i++){
00250         velVec[n - i] = velVec[n-i-1];
00251         sum += velVec[n-i];
00252         }
00253     velVec[0] = out;
00254     return sum/(float)n;
00255     }
00256     
00257 float PositionSensorEncoder::GetElecVelocity(){
00258     return _ppairs*GetMechVelocity();
00259     }
00260     
00261 void PositionSensorEncoder::ZeroEncoderCount(void){
00262     if (ZSense->read() == 1 & flag == 0){
00263         if (ZSense->read() == 1){
00264             GPIOC->ODR ^= (1 << 4);   
00265             TIM3->CNT = 0x000;
00266             //state = !state;
00267             //ZTest->write(state);
00268             GPIOC->ODR ^= (1 << 4);
00269             //flag = 1;
00270         }
00271         }
00272     }
00273 
00274 void PositionSensorEncoder::ZeroPosition(void){
00275     
00276     }
00277     
00278 void PositionSensorEncoder::ZeroEncoderCountDown(void){
00279     if (ZSense->read() == 0){
00280         if (ZSense->read() == 0){
00281             GPIOC->ODR ^= (1 << 4);
00282             flag = 0;
00283             float dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f;
00284             if(dir != dir){
00285                 dir = dir;
00286                 rotations +=  dir;
00287                 }
00288 
00289             GPIOC->ODR ^= (1 << 4);
00290 
00291         }
00292         }
00293     }
00294 void PositionSensorEncoder::SetElecOffset(float offset){
00295     
00296     }
00297     
00298 int PositionSensorEncoder::GetRawPosition(void){
00299     return 0;
00300     }
00301     
00302 int PositionSensorEncoder::GetCPR(){
00303     return _CPR;
00304     }
00305     
00306 
00307 void PositionSensorEncoder::WriteLUT(int new_lut[128]){
00308     memcpy(offset_lut, new_lut, sizeof(offset_lut));
00309     }