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     raw = spi->write(0);
00033     //raw = raw>>2;                                                             //Extract last 14 bits
00034     raw &= 0x7FFF;
00035     raw = raw>>1;
00036     GPIOA->ODR |= (1 << 15);
00037     int off_1 = offset_lut[raw>>7];
00038     int off_2 = offset_lut[((raw>>7)+1)%128];
00039     int off_interp = off_1 + ((off_2 - off_1)*(raw - ((raw>>7)<<7))>>7);        // Interpolate between lookup table entries
00040     int angle = raw + off_interp;                                               // Correct for nonlinearity with lookup table from calibration
00041     if(angle - old_counts > _CPR/2){
00042         rotations -= 1;
00043         }
00044     else if (angle - old_counts < -_CPR/2){
00045         rotations += 1;
00046         }
00047     
00048     old_counts = angle;
00049     oldModPosition = modPosition;
00050     modPosition = ((2.0f*PI * ((float) angle))/ (float)_CPR);
00051     position = (2.0f*PI * ((float) angle+(_CPR*rotations)))/ (float)_CPR;
00052     MechPosition = position - MechOffset;
00053     float elec = ((2.0f*PI/(float)_CPR) * (float) ((_ppairs*angle)%_CPR)) + ElecOffset;
00054     if(elec < 0) elec += 2.0f*PI;
00055     else if(elec > 2.0f*PI) elec -= 2.0f*PI ; 
00056     ElecPosition = elec;
00057     
00058     float vel;
00059     //if(modPosition<.1f && oldModPosition>6.1f){
00060 
00061     if((modPosition-oldModPosition) < -3.0f){
00062         vel = (modPosition - oldModPosition + 2.0f*PI)/dt;
00063         }
00064     //else if(modPosition>6.1f && oldModPosition<0.1f){
00065     else if((modPosition - oldModPosition) > 3.0f){
00066         vel = (modPosition - oldModPosition - 2.0f*PI)/dt;
00067         }
00068     else{
00069         vel = (modPosition-oldModPosition)/dt;
00070     }    
00071     
00072     int n = 40;
00073     float sum = vel;
00074     for (int i = 1; i < (n); i++){
00075         velVec[n - i] = velVec[n-i-1];
00076         sum += velVec[n-i];
00077         }
00078     velVec[0] = vel;
00079     MechVelocity =  sum/((float)n);
00080     ElecVelocity = MechVelocity*_ppairs;
00081     ElecVelocityFilt = 0.99f*ElecVelocityFilt + 0.01f*ElecVelocity;
00082     }
00083 
00084 int PositionSensorAM5147::GetRawPosition(){
00085     return raw;
00086     }
00087 
00088 float PositionSensorAM5147::GetMechPositionFixed(){
00089     return MechPosition+MechOffset;
00090     }
00091     
00092 float PositionSensorAM5147::GetMechPosition(){
00093     return MechPosition;
00094     }
00095 
00096 float PositionSensorAM5147::GetElecPosition(){
00097     return ElecPosition;
00098     }
00099 
00100 float PositionSensorAM5147::GetElecVelocity(){
00101     return ElecVelocity;
00102     }
00103 
00104 float PositionSensorAM5147::GetMechVelocity(){
00105     return MechVelocity;
00106     }
00107 
00108 void PositionSensorAM5147::ZeroPosition(){
00109     rotations = 0;
00110     MechOffset = 0;
00111     Sample(.00025f);
00112     MechOffset = GetMechPosition();
00113     }
00114     
00115 void PositionSensorAM5147::SetElecOffset(float offset){
00116     ElecOffset = offset;
00117     }
00118 void PositionSensorAM5147::SetMechOffset(float offset){
00119     MechOffset = offset;
00120     }
00121 
00122 int PositionSensorAM5147::GetCPR(){
00123     return _CPR;
00124     }
00125 
00126 
00127 void PositionSensorAM5147::WriteLUT(int new_lut[128]){
00128     memcpy(offset_lut, new_lut, sizeof(offset_lut));
00129     }
00130     
00131 
00132 
00133 PositionSensorEncoder::PositionSensorEncoder(int CPR, float offset, int ppairs) {
00134     _ppairs = ppairs;
00135     _CPR = CPR;
00136     _offset = offset;
00137     MechPosition = 0;
00138     out_old = 0;
00139     oldVel = 0;
00140     raw = 0;
00141     
00142     // Enable clock for GPIOA
00143     __GPIOA_CLK_ENABLE(); //equivalent from hal_rcc.h
00144  
00145     GPIOA->MODER   |= GPIO_MODER_MODER6_1 | GPIO_MODER_MODER7_1 ;           //PA6 & PA7 as Alternate Function   /*!< GPIO port mode register,               Address offset: 0x00      */
00146     GPIOA->OTYPER  |= GPIO_OTYPER_OT_6 | GPIO_OTYPER_OT_7 ;                 //PA6 & PA7 as Inputs               /*!< GPIO port output type register,        Address offset: 0x04      */
00147     GPIOA->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR6 | GPIO_OSPEEDER_OSPEEDR7 ;     //Low speed                         /*!< GPIO port output speed register,       Address offset: 0x08      */
00148     GPIOA->PUPDR   |= GPIO_PUPDR_PUPDR6_1 | GPIO_PUPDR_PUPDR7_1 ;           //Pull Down                         /*!< GPIO port pull-up/pull-down register,  Address offset: 0x0C      */
00149     GPIOA->AFR[0]  |= 0x22000000 ;                                          //AF02 for PA6 & PA7                /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
00150     GPIOA->AFR[1]  |= 0x00000000 ;                                          //nibbles here refer to gpio8..15   /*!< GPIO alternate function registers,     Address offset: 0x20-0x24 */
00151    
00152     // configure TIM3 as Encoder input
00153     // Enable clock for TIM3
00154     __TIM3_CLK_ENABLE();
00155  
00156     TIM3->CR1   = 0x0001;                                                   // CEN(Counter ENable)='1'     < TIM control register 1
00157     TIM3->SMCR  = TIM_ENCODERMODE_TI12;                                     // SMS='011' (Encoder mode 3)  < TIM slave mode control register
00158     TIM3->CCMR1 = 0x1111;                                                   // CC1S='01' CC2S='01'         < TIM capture/compare mode register 1, maximum digital filtering
00159     TIM3->CCMR2 = 0x0000;                                                   //                             < TIM capture/compare mode register 2
00160     TIM3->CCER  = 0x0011;                                                   // CC1P CC2P                   < TIM capture/compare enable register
00161     TIM3->PSC   = 0x0000;                                                   // Prescaler = (0+1)           < TIM prescaler
00162     TIM3->ARR   = CPR;                                                      // IM auto-reload register
00163   
00164     TIM3->CNT = 0x000;  //reset the counter before we use it  
00165     
00166     // Extra Timer for velocity measurement
00167     
00168     __TIM2_CLK_ENABLE();
00169     TIM3->CR2 = 0x030;                                                      //MMS = 101
00170     
00171     TIM2->PSC = 0x03;
00172     //TIM2->CR2 |= TIM_CR2_TI1S;
00173     TIM2->SMCR = 0x24;                                                      //TS = 010 for ITR2, SMS = 100 (reset counter at edge)
00174     TIM2->CCMR1 = 0x3;                                                      // CC1S = 11, IC1 mapped on TRC
00175     
00176     //TIM2->CR2 |= TIM_CR2_TI1S;
00177     TIM2->CCER |= TIM_CCER_CC1P;
00178     //TIM2->CCER |= TIM_CCER_CC1NP;
00179     TIM2->CCER |= TIM_CCER_CC1E;
00180     
00181     
00182     TIM2->CR1 = 0x01;                                                       //CEN,  enable timer
00183     
00184     TIM3->CR1   = 0x01;                                                     // CEN
00185     ZPulse = new InterruptIn(PC_4);
00186     ZSense = new DigitalIn(PC_4);
00187     //ZPulse = new InterruptIn(PB_0);
00188     //ZSense = new DigitalIn(PB_0);
00189     ZPulse->enable_irq();
00190     ZPulse->rise(this, &PositionSensorEncoder::ZeroEncoderCount);
00191     //ZPulse->fall(this, &PositionSensorEncoder::ZeroEncoderCountDown);
00192     ZPulse->mode(PullDown);
00193     flag = 0;
00194 
00195     
00196     //ZTest = new DigitalOut(PC_2);
00197     //ZTest->write(1);
00198     }
00199     
00200 void PositionSensorEncoder::Sample(float dt){
00201     
00202     }
00203 
00204  
00205 float PositionSensorEncoder::GetMechPosition() {                            //returns rotor angle in radians.
00206     int raw = TIM3->CNT;
00207     float unsigned_mech = (6.28318530718f/(float)_CPR) * (float) ((raw)%_CPR);
00208     return (float) unsigned_mech;// + 6.28318530718f* (float) rotations;
00209 }
00210 
00211 float PositionSensorEncoder::GetElecPosition() {                            //returns rotor electrical angle in radians.
00212     int raw = TIM3->CNT;
00213     float elec = ((6.28318530718f/(float)_CPR) * (float) ((_ppairs*raw)%_CPR)) - _offset;
00214     if(elec < 0) elec += 6.28318530718f;
00215     return elec;
00216 }
00217 
00218 
00219     
00220 float PositionSensorEncoder::GetMechVelocity(){
00221 
00222     float out = 0;
00223     float rawPeriod = TIM2->CCR1; //Clock Ticks
00224     int currentTime = TIM2->CNT;
00225     if(currentTime > 2000000){rawPeriod = currentTime;}
00226     float  dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f;    // +/- 1
00227     float meas = dir*180000000.0f*(6.28318530718f/(float)_CPR)/rawPeriod; 
00228     if(isinf(meas)){ meas = 1;}
00229     out = meas;
00230     //if(meas == oldVel){
00231      //   out = .9f*out_old;
00232      //   }
00233     
00234  
00235     oldVel = meas;
00236     out_old = out;
00237     int n = 16;
00238     float sum = out;
00239     for (int i = 1; i < (n); i++){
00240         velVec[n - i] = velVec[n-i-1];
00241         sum += velVec[n-i];
00242         }
00243     velVec[0] = out;
00244     return sum/(float)n;
00245     }
00246     
00247 float PositionSensorEncoder::GetElecVelocity(){
00248     return _ppairs*GetMechVelocity();
00249     }
00250     
00251 void PositionSensorEncoder::ZeroEncoderCount(void){
00252     if (ZSense->read() == 1 & flag == 0){
00253         if (ZSense->read() == 1){
00254             GPIOC->ODR ^= (1 << 4);   
00255             TIM3->CNT = 0x000;
00256             //state = !state;
00257             //ZTest->write(state);
00258             GPIOC->ODR ^= (1 << 4);
00259             //flag = 1;
00260         }
00261         }
00262     }
00263 
00264 void PositionSensorEncoder::ZeroPosition(void){
00265     
00266     }
00267     
00268 void PositionSensorEncoder::ZeroEncoderCountDown(void){
00269     if (ZSense->read() == 0){
00270         if (ZSense->read() == 0){
00271             GPIOC->ODR ^= (1 << 4);
00272             flag = 0;
00273             float dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f;
00274             if(dir != dir){
00275                 dir = dir;
00276                 rotations +=  dir;
00277                 }
00278 
00279             GPIOC->ODR ^= (1 << 4);
00280 
00281         }
00282         }
00283     }
00284 void PositionSensorEncoder::SetElecOffset(float offset){
00285     
00286     }
00287     
00288 int PositionSensorEncoder::GetRawPosition(void){
00289     return 0;
00290     }
00291     
00292 int PositionSensorEncoder::GetCPR(){
00293     return _CPR;
00294     }
00295     
00296 
00297 void PositionSensorEncoder::WriteLUT(int new_lut[128]){
00298     memcpy(offset_lut, new_lut, sizeof(offset_lut));
00299     }