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