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