![](/media/cache/profiles/2012_sf_avc_095.jpg.50x50_q85.jpg)
Code for autonomous rover for Sparkfun AVC. DataBus won 3rd in 2012 and the same code was used on Troubled Child, a 1986 Jeep Grand Wagoneer to win 1st in 2014.
Dependencies: mbed Watchdog SDFileSystem DigoleSerialDisp
Sensors/Sensors.cpp
- Committer:
- shimniok
- Date:
- 2013-06-06
- Revision:
- 2:fbc6e3cf3ed8
- Parent:
- 0:a6a169de725f
- Child:
- 12:5dfa1ab47838
File content as of revision 2:fbc6e3cf3ed8:
/* MinIMU-9-Arduino-AHRS Pololu MinIMU-9 + Arduino AHRS (Attitude and Heading Reference System) Copyright (c) 2011 Pololu Corporation. http://www.pololu.com/ MinIMU-9-Arduino-AHRS is based on sf9domahrs by Doug Weibel and Jose Julio: http://code.google.com/p/sf9domahrs/ sf9domahrs is based on ArduIMU v1.5 by Jordi Munoz and William Premerlani, Jose Julio and Doug Weibel: http://code.google.com/p/ardu-imu/ MinIMU-9-Arduino-AHRS is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. MinIMU-9-Arduino-AHRS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with MinIMU-9-Arduino-AHRS. If not, see <http://www.gnu.org/licenses/>. */ #include "Sensors.h" #include "debug.h" #include "stdio.h" #define GYRO_SCALE 14.49787 // TODO: is the sign right here?? yes, see g_sign #define VFF 50.0 // voltage filter factor ///////////////////// MAGNETOMETER CALIBRATION Sensors::Sensors(): gps(p26, p25), _voltage(p19), // Voltage from sensor board _current(p20), // Current from sensor board _left(p30), // left wheel encoder _right(p29), // Right wheel encoder _gyro(p28, p27), // MinIMU-9 gyro _compass(p28, p27), // MinIMU-9 compass/accelerometer _rangers(p28, p27), // Arduino ADC to I2C _cam(p28, p27) { for (int i=0; i < 3; i++) { m_offset[i] = 0; m_scale[i] = 1; } // TODO: parameterize g_scale[0] = 1; g_scale[1] = 1; g_scale[2] = GYRO_SCALE; g_sign[0] = 1; g_sign[1] = -1; g_sign[2] = -1; a_sign[0] = -1; a_sign[1] = 1; a_sign[2] = 1; m_sign[0] = 1; m_sign[1] = -1; m_sign[2] = -1; // upside down mounting //g_sign[3] = {1,1,1}; //a_sign[3] = {-1,-1,-1}; //m_sign[3] = {1,1,1}; } /* Compass_Calibrate * * Set the offset and scale calibration for the compass */ void Sensors::Compass_Calibrate(float offset[3], float scale[3]) { for (int i=0; i < 3; i++) { m_offset[i] = offset[i]; m_scale[i] = scale[i]; } return; } void Sensors::Read_Encoders() { // Odometry leftCount = _left.read(); rightCount = _right.read(); leftTotal += leftCount; rightTotal += rightCount; // TODO--> sanity check on encoders; if difference between them // is huge, what do we do? Slipping wheel? Skidding wheel? // front encoders would be ideal as additional sanity check // TODO: move this into scheduler?? // TODO: how do we track distance, should we only check distance everytime we do a nav/pos update? // TODO: get rid of state variable lrEncDistance = (WHEEL_CIRC / WHEEL_STRIPES) * (double) leftCount; rrEncDistance = (WHEEL_CIRC / WHEEL_STRIPES) * (double) rightCount; //encDistance = (lrEncDistance + rrEncDistance) / 2.0; // compute speed from time between ticks int leftTime = _left.readTime(); int rightTime = _right.readTime(); // We could also supplement this with distance/time calcs once we get up to a higher // speed and encoder quantization error is lower // To reduce asymmetry of the encoder operation, we're only reading time // between rising ticks. So that means half the wheel stripes if (leftTime <= 0) { lrEncSpeed = 0; } else { lrEncSpeed = (2.0 * WHEEL_CIRC / WHEEL_STRIPES) / ((float) leftTime * 1e-6); } if (rightTime <= 0) { rrEncSpeed = 0; } else { rrEncSpeed = (2.0 * WHEEL_CIRC / WHEEL_STRIPES) / ((float) rightTime * 1e-6); } // Dead band if (lrEncSpeed < 0.1) lrEncSpeed = 0; if (rrEncSpeed < 0.1) rrEncSpeed = 0; // TODO: 3 use more sophisticated approach where we count if any ticks have happened lately // and if not, reset the speed encSpeed = (lrEncSpeed + rrEncSpeed) / 2.0; } void Sensors::Read_Gyro() { _gyro.read(g); gTemp = (int) _gyro.readTemp(); gyro[_x_] = g_sign[_x_] * (g[_x_] - g_offset[_x_]); // really need to scale this too gyro[_y_] = g_sign[_y_] * (g[_y_] - g_offset[_y_]); // really need to scale this too gyro[_z_] = (g_sign[_z_] * (g[_z_] - g_offset[_z_])) / g_scale[_z_]; return; } // Reads x,y and z accelerometer registers void Sensors::Read_Accel() { _compass.readAcc(a); accel[_x_] = a_sign[_x_] * (a[_x_] - a_offset[_x_]); accel[_y_] = a_sign[_y_] * (a[_y_] - a_offset[_y_]); accel[_z_] = a_sign[_z_] * (a[_z_] - a_offset[_z_]); return; } void Sensors::Read_Compass() { _compass.readMag(m); // TODO: parameterize sign // adjust for compass axis offsets and scale for (int i=0; i < 3; i++) { mag[i] = ((float) m[i] - m_offset[i]) * m_scale[i] * m_sign[i]; } //fprintf(stdout, "m_offset=(%5.5f,%5.5f,%5.5f)\n", ahrs.c_magnetom[0],ahrs.c_magnetom[1],ahrs.c_magnetom[2]); return; } /* doing some crude gryo and accelerometer offset calibration here * */ void Sensors::Calculate_Offsets() { int samples=128; for (int i=0; i < 3; i++) { g_offset[i] = 0; a_offset[i] = 0; } for(int i=0; i < samples; i++) { // We take some readings... Read_Gyro(); Read_Accel(); wait(0.010); // sample at 100hz for(int y=0; y < 3; y++) { // accumulate values g_offset[y] += g[y]; a_offset[y] += a[y]; } } for(int y=0; y < 3; y++) { g_offset[y] /= samples; a_offset[y] /= samples; } //TODO: if we ever get back to using accelerometer, do something about this. //a_offset[_z_] -= GRAVITY * a_sign[_z_]; // I don't get why we're doing this...? } void Sensors::Compass_Heading() { /* float MAG_X; float MAG_Y; float cos_roll; float sin_roll; float cos_pitch; float sin_pitch; // See DCM.cpp Drift_correction() // umm... doesn't the dcm already have this info in it?! cos_roll = cos(ahrs.roll); sin_roll = sin(ahrs.roll); cos_pitch = cos(ahrs.pitch); sin_pitch = sin(ahrs.pitch); // Tilt compensated Magnetic filed X: MAG_X = mag[_x_] * cos_pitch + mag[_y_] * sin_roll * sin_pitch + mag[_z_] * cos_roll * sin_pitch; // Tilt compensated Magnetic filed Y: MAG_Y = mag[_y_] * cos_roll - mag[_z_] * sin_roll; // Magnetic Heading ahrs.MAG_Heading = atan2(-MAG_Y,MAG_X); */ } void Sensors::getRawMag(int rawmag[3]) { Read_Compass(); for (int i=0; i < 3; i++) { rawmag[i] = m[i]; } } // getCurrent is a macro defined above float Sensors::getVoltage() { static float filter = -1.0; float v = _voltage * 3.3 * 4.12712; // 242.3mV/V // TODO: median filter to eliminate spikes if (filter < 0) { filter = v * VFF; } else { filter += (v - filter/VFF); } return (filter / VFF); } float Sensors::getCurrent() { /*static bool first=true; static float history[3]; float tmp; float sort[3]; if (first) { first = false; history[0] = history[1] = history[2] = _current; } else { sort[0] = history[0] = history[1]; sort[1] = history[1] = history[2]; sort[2] = history[2] = _current; } BubbleSort(sort, 3);*/ return (_current * 3.3 * 13.6612); // 73.20mV/A } void Sensors::Read_Power() { // TODO: exponential or median filtering on these to get rid of spikes // voltage = getVoltage(); current = getCurrent(); return; } float clampIRRanger(float x) { float y=x; if (y < 0.1) y = 0.1; if (y > 5.0) y = 5.0; return y; } void Sensors::Read_Camera() { char count; //char data[128]; //char addr=0x80; /* struct { int color; int x1; int y1; int x2; int y2; } blob; */ /* I2C START BIT WRITE: 0xA0 ACK WRITE: 0x00 ACK I2C START BIT WRITE: 0xA1 ACK READ: 0x01 ACK 0x02 ACK 0x03 ACK 0x04 ACK 0x05 ACK 0x06 ACK 0x07 ACK 0x08 ACK 0x09 ACK 0x0A NACK I2C STOP BIT */ _cam.start(); _cam.write(0x11<<1); _cam.write(0x01); // command to send box data _cam.start(); _cam.write((0x11<<1 | 0x01)); count = _cam.read(1); // number of boxes tracked if (count > 8) count = 8; //fprintf(stdout, "----------\n%d\n", count); int x=0; for (int i=0; i < count; i++) { //fprintf(stdout, "%d: ", i); for (int j=0; j < 5; j++) { //data[x] = _cam.read(1); //fprintf(stdout, "%d ", data[x]); x++; } //fprintf(stdout, "\n"); } _cam.read(0); // easiest to just read one more byte then NACK it _cam.stop(); } void Sensors::Read_Rangers() { char data[2]; // Sharp GP2Y0A710YK0F static float m=288.12; // slope adc=m(dist) + b static float b=219.3; static float m_per_lsb=0.004883/0.38583; // 0.004883mV/lsb * 0.0098in/lsb * 1in/0.0254m = m/lsb _rangers.start(); data[0] = (0x11<<1 | 0x01); // send address + read = 1 _rangers.write(data[0]); // send address ranger[0] = (int) _rangers.read(1) | ((int) _rangers.read(1)) << 8; ranger[1] = (int) _rangers.read(1) | ((int) _rangers.read(1)) << 8; ranger[2] = (int) _rangers.read(1) | ((int) _rangers.read(0)) << 8; // don't ack the last byte _rangers.stop(); /* for (int q=0; q<3; q++) fprintf(stdout, "%04x ", ranger[q]); fprintf(stdout, "\n"); */ if (ranger[0] < 86) { rightRanger = 999.0; } else if (ranger[0] > 585) { rightRanger = 20.0; } else { // Sharp GP2Y0A02YK0F rightRanger = 1/(8.664e-005*ranger[0]-0.0008); // IR distance, meters } // Compute distances leftRanger = clampIRRanger( m/(ranger[1]-b) ); // IR distance, meters // Sonar centerRanger = ranger[2] * (m_per_lsb); // Sonar distance, metersmv/in=0.0098, mv/lsb=0.0049 } /** perform bubble sort * for median filtering */ void Sensors::BubbleSort(float *num, int numLength) { float temp; // holding variable bool flag=true; for(int i = 1; (i <= numLength) && flag; i++) { flag = false; for (int j = 0; j < (numLength -1); j++) { if (num[j+1] > num[j]) { // ascending order simply changes to < temp = num[j]; // swap elements num[j] = num[j+1]; num[j+1] = temp; flag = true; } } } return; //arrays are passed to functions by address; nothing is returned }