F14: Team4-Self Driving Car - AUG

Introduction

This project is aimed at developing a 1/10 RC car with a self-driving capability based on controller interaction over the CAN (Controller Area Network) bus. With the advent of driverless cars, we felt the need to develop a scaled-down version that can maneuver itself through co-ordinates fed by Google maps and correct its course when it sees an obstacle. To achieve this objective, we plan to integrate 6 controllers dedicated to specific roles that can pass messages over a common CAN communication bus. In addition, the prototype would involve an Android mobile application for data monitoring and controlling purpose to keep a track of the car remotely and feed it the required checkpoints to reach its destination. The car would comprise of three modes of operation namely; home, map and free run. In the home mode, the car would be guided to its home destination (which is preset to Boccardo Business center) from its current location. In the map mode, the user can feed in the desired destination through the google maps interface which the car would follow based on the co-ordinates and heading provided by its GPS and compass respectively. The free run mode will convert the mobile phone into a remote device capable of controlling the speed and direction of the car based on the accelerometer and gyroscope enabled on the device. In this way, the user can take control of the car at any given time. Below is the high-level block diagram of the entire system.

Startup

The following series of events would take place when the car is powered on:

1. The GPS would wait for a satellite fix of at least 3 satellites, which would relay the information to the Android device through its controller over the CAN bus.
   
2. If the user selects the Map mode, he would be required to enter the co-ordinates of the destination visually by dropping a marker on the map.
   
3. The app would compute the checkpoints and distance and feed the information to the on-board communication controller.
   
4. The first checkpoint is sent to the GPS and master controller, which would co-ordinate the events for the motor and sensor controllers.
   
5. Any obstacle detected by the ultrasonic sensors would override the current path and try to avoid the obstacle.
   
6. The master controller would compute the course correction and reconfigure the required controllers once the car has passed the obstacle.
   
7. The IO controller is responsible for monitoring the data on the CAN bus and displaying the information on the mounted LCD panel. The light and battery sensors are also connected to the IO controller, which automatically turn on the headlights and monitor the battery health respectively.
   
8. Start/Stop triggers can be given to the car remotely using the mobile application as well as from the on-board LCD.
   
9. Once the car reaches the first checkpoint, it will request for the second one from the communication controller and pass it over to the master. In this way, the process continues till the car reaches the destination.
   
10. Home mode operates in a similar way but with a fixed destination and the free run mode is pretty much self-explanatory
    

Highlights

1. Self-Navigation with Obstacle avoidance on all sides on the car.
   
2. Google maps interface for location monitoring and destination setting along with checkpoint computation.
   
3. Three modes of operation – Home, Map and Free run.
   
4. Three choices of speed – Slow (8 mph), Normal (10 mph) and Turbo (12 mph).
   
5. Automatic checkpoint detection and request for checkpoint system.
   
6. Headlights using lights sensors and brake lights on the tail.
   
7. Battery health monitoring.
   
8. Visual picturization of sensor data relative the car on the android application.
   
9. Speed gauge and compass needle for easier visualization on the application.
   
10. Kill switch for instant power off.
    
11. Free run mode for remotely controlling the car.
    

Team Members & Responsibilities

• Sensor Controller:
  • Chinmay Vaidya
    
  • Manuj Shinkar
    
• Motor Controller
  • Viral Agrawal
    
  • Mitesh Sanghvi
    
• I/O Unit:
  • Tej Kogekar
  • Mayur Salve
    
• Communication Bridge + Android:
  • Jayanth Nallapothula
    
  • Manish Mandalik
    
  • Kwun Fung Ng (Daniel)
    
• Geographical Controller:
  • Ishan Bhavsar
    
  • Tanuj Chirimar
    
  • Sushant Potdar
    
• Master Controller:
  • Dhaval Parikh
    
  • Harita Dhiren Parekh
    
  • Rutwik Kulkarni
    

Parts List & Cost

S.R.	Description	Manufacturer	Part Number	Qty	Total Cost
1	SJOne Board	-	-	6	$480.00
2	RC Car	Traxxas	-	1	$240.00
3	Ultrasonic Sensor	Parallax	28015	3	$69.00
4	ADC Sensor	Maxbotix	MB1000	1	$29.00
5	LDR	-	-	1	$1.00
6	Battery Health Monitoring Resistors	-	-	2	$2.00
7	IR Sensor (Used as Speed Encoder)	-	-	1	$15.00
8	GLCD with Touchscreen	4D Systems	uLCD-32PTU	1	$106.00
9	Tact Switches	-	-	4	$2.00
10	LEDs with Holders	-	-	4	$2.00
11	XBee Module	Digi	XBee Series1	2	$40.00
12	Bluetooth Module	Microchip	RN42XVP-I/RM	1	$20.00
13	GPS Module	Sparkfun	GPS-11058	1	$49.95
14	Compass Module	Adafruit	HMC5883L	1	$9.95.00
15	CAN Transceiver (Free Samples)	Microchip	MCP2551	6	$0.00
16	Linear Voltage Regulator (Free Sample)	LT	LT1083-5	1	$0.00
17	Miscellaneous	-	-	-	$20.00
	Total (Excluding Shipping and Taxes				$0000.00

Design & Implementation

CAN 11-bit ID Format

MSG	DST	SRC
5 bits (11-6)	3 bits (5-3)	3 bits (2-0)

Controller ID Table

Controller ID	Controller Type
001	Motor Controller
010	Master Controller
011	Sensor Controller
100	GEO Controller
110	Communication Bridge + Android Controller
111	I/O Controller

Controller Communication Table

Master Controller Communication Table

S.R.	Message Number	Destination	Message Name (MSG_FUNCTION)	Data Layout of Data Sent over CAN (byte[0] = total number of data bytes)
1	0x042	All	RESET	NO DATA
2	0x082	All	POWERUP_SYN	NO DATA
3	0x102	All	POWERUP_ACK	Msg1 : byte[1]  : (uint8_t) version Msg1 : byte[2-3] : (uint16_t) year Msg1 : byte[4]  : (uint8_t) month Msg1 : byte[5]  : (uint8_t) date Msg1 : byte[6]  : (uint8_t) dayofweek Msg1 : byte[7]  : (uint8_t) hour Msg2 : byte[1]  : (uint8_t) minute Msg2 : byte[2]  : (uint8_t) second
4	0x142	All	HEARTBEAT	Msg1 : byte[1-2] : (uint16_t) rx_count Msg1 : byte[3-4] : (uint16_t) rx_bytes Msg1 : byte[5-6] : (uint16_t) tx_count Msg1 : byte[7]  : (uint16_t) tx_bytes Msg2 : byte[1]  : (uint16_t) tx_bytes
5	0x3CA	Motor	SPEED_DIR_COMMAND	Msg1 : byte[1]  : (uint8_t) speed Msg1 : byte[2]  : (uint8_t) direction Msg1 : byte[3]  : (uint8_t) brake

Motor Controller Communication Table

S.R.	Message Number	Destination	Message Name (MSG_FUNCTION)	Data Layout of Data Sent over CAN (byte[0] = total number of data bytes)
1	0x0D1	Master	POWERUP_SYN_ACK	Msg1 : byte[1]  : (uint8_t) version
2	0x191	Master	HEARTBEAT_ACK	Msg1 : byte[1-2] : (uint16_t) rx_count Msg1 : byte[3-4] : (uint16_t) rx_bytes Msg1 : byte[5-6] : (uint16_t) tx_count Msg1 : byte[7]  : (uint16_t) tx_bytes Msg2 : byte[1]  : (uint16_t) tx_bytes
3	0x341	Master, I/O and Communication Bridge	SPEED_ENCODER_DATA	Msg1 : byte[1]  : (uint8_t) speed Msg1 : byte[2]  : (uint8_t) dir Msg1 : byte[3]  : (uint8_t) brake

GEO Controller Communication Table

S.R.	Message Number	Destination	Message Name (MSG_FUNCTION)	Data Layout of Data Sent over CAN (byte[0] = total number of data bytes)
1	0x0D4	Master	POWERUP_SYN_ACK	Msg1 : byte[1]  : (uint8_t) version
2	0x194	Master	HEARTBEAT_ACK	Msg1 : byte[1-2] : (uint16_t) rx_count Msg1 : byte[3-4] : (uint16_t) rx_bytes Msg1 : byte[5-6] : (uint16_t) tx_count Msg1 : byte[7]  : (uint16_t) tx_bytes Msg2 : byte[1]  : (uint16_t) tx_bytes
3	0x384	Master, I/O and Communication	GEO_HEADING_DATA	Msg1 : byte[1]  : (uint8_t) current_angle Msg1 : byte[2]  : (uint8_t) desired_angle Msg1 : byte[3]  : (uint8_t) destination_reached Msg1 : byte[4]  : (uint8_t) is_valid
4	0x484	I/O and Communication Bridge	GEO_LOCATION_DATA	Msg1 : byte[1-4] : (float) latitude Msg1 : byte[5-7] : (float) longitude Msg2 : byte[1]  : (float) longitude Msg2 : byte[2-3] : (uint16_t) dist_to_final_destination Msg2 : byte[4-5] : (uint16_t) dist_to_next_checkpoint Msg2 : byte[6]  : (uint8_t) is_valid
5	0x2AC	Communication Bridge	CHECKPOINT_REQUEST	Msg1 : byte[1]  : (uint8_t) checkpoint_num

Communication Bridge + Android Controller Communication Table

S.R.	Message Number	Destination	Message Name (MSG_FUNCTION)	Data Layout of Data Sent over CAN (byte[0] = total number of data bytes)
1	0x0D5	Master	POWERUP_SYN_ACK	Msg1 : byte[1]  : (uint8_t) version
2	0x195	Master	HEARTBEAT_ACK	Msg1 : byte[1-2] : (uint16_t) rx_count Msg1 : byte[3-4] : (uint16_t) rx_bytes Msg1 : byte[5-6] : (uint16_t) tx_count Msg1 : byte[7]  : (uint16_t) tx_bytes Msg2 : byte[1]  : (uint16_t) tx_bytes
3	0x1D5	Master and I/O	CAR_PAUSE	NO DATA
4	0x215	Master and I/O	CAR_RESUME	NO DATA
5	0x425	Geographical	CHECKPOINT_DATA	Msg1 : byte[1-4] : (float) latitude Msg1 : byte[5-7] : (float) longitude Msg2 : byte[1]  : (float) longitude Msg2 : byte[2-3] : (uint16_t) total_distance Msg2 : byte[4]  : (uint8_t) checkpoint_num Msg2 : byte[5]  : (uint8_t) is_new_route Msg2 : byte[6]  : (uint8_t) is_final_checkpoint
6	0x2C5	Master, I/O, Communication Bridge and Motor	DRIVE_MODE	Msg1 : byte[1]  : (uint8_t) mode
7	0x255	Master	FREE_RUN_DIR	Msg1 : byte[1]  : (uint8_t) speed Msg1 : byte[2]  : (uint8_t) turn Msg1 : byte[3]  : (uint8_t) direction

Sensor Controller Communication Table

S.R.	Message Number	Destination	Message Name (MSG_FUNCTION)	Data Layout of Data Sent over CAN (byte[0] = total number of data bytes)
1	0x0D3	Master	POWERUP_SYN_ACK	Msg1 : byte[1]  : (uint8_t) version
2	0x193	Master	HEARTBEAT_ACK	Msg1 : byte[1-2] : (uint16_t) rx_count Msg1 : byte[3-4] : (uint16_t) rx_bytes Msg1 : byte[5-6] : (uint16_t) tx_count Msg1 : byte[7]  : (uint16_t) tx_bytes Msg2 : byte[1]  : (uint16_t) tx_bytes
3	0x303	Master, I/O and Communication Bridge	DIST_SENSOR_DATA	Msg1 : byte[1]  : (uint8t) left Msg1 : byte[2]  : (uint8t) middle Msg1 : byte[3]  : (uint8t) right Msg1 : byte[4]  : (uint8t) back
4	0x443	I/O and Communication Bridge	OTHER_SENSOR_DATA	Msg1 : byte[1]  : (uint8t) battery Msg1 : byte[2]  : (uint8t) light

I/O Controller Communication Table

S.R.	Message Number	Destination	Message Name (MSG_FUNCTION)	Data Layout of Data Sent over CAN (byte[0] = total number of data bytes)
1	0x056	Master	RESET	NO DATA
2	0x0D6	Master	POWERUP_SYN_ACK	Msg1 : byte[1]  : (uint8_t) version
3	0x196	Master	HEARTBEAT_ACK	Msg1 : byte[1-2] : (uint16_t) rx_count Msg1 : byte[3-4] : (uint16_t) rx_bytes Msg1 : byte[5-6] : (uint16_t) tx_count Msg1 : byte[7]  : (uint16_t) tx_bytes Msg2 : byte[1]  : (uint16_t) tx_bytes
4	0x1D4	Master and I/O	CAR_PAUSE	NO DATA
5	0x214	Master and I/O	CAR_RESUME	NO DATA
6	0x2C4	Master, I/O and Motor	DRIVE_MODE	Msg1 : byte[1]  : (uint8_t) mode

Communication Bridge + Android Controller

Introduction

The communication bridge is a connection between Android application and other controllers on the RC car. The Android application is written in Java and there are xBee(ZigBee) chip sets along with Bluetooth as a bridge connection. The major functions of the bridge is

1. Allow a user to see sensor values, car speed, etc.
2. Allow a user to select a destination from Google Earth.

Modules

1. xBee Module:
The following pictures shown the chip set of xBee which is using zigbee to communicate with each other:

Figure1:

xBee Chipset

Features: Long Range Data Integrity Indoor/ Urban: up to 100’(30m) Outdoor line-of-sight: up to 300’ (90m) Transmit Power: 1mW(0dBm) Receiver Sensitivity: -92dBm Advanced Networking & Security Retries and Acknowledgements DSSS (Direct Sequence Spread Spectrum) Each direct sequence channels has over 65,000 unique network addresses available Source/ Destination Addressing Unicast & Broadcast Communications Point-to-point, point-to-multipoint and peer-to-peer topologies supported Low Power TX Peak Current: 45mA(@3.3V) RX Current: 50mA(@3.3V) Power-down Current: <10μA ADC and I/O line support Analog-to-digital conversion, Digital I/O Line Passing Easy-to-use Free X-CTU Software AT and APU Command Modes for configuring module parameters

2. Bluetooth Module (RN-421):
The following picture is the Bluetooth module RN-42I:

Figure1: Bluetooth Module RN-421

Features:

• Fully qualified Bluetooth version 2.1 module, support version 2.1+Enhanced Data Rate (EDR)
• Backwards compatible with Bluetooth version 2.0, 1.2 and 1.1.
• Low power (26uA sleep, 3mA connected, 30mA transmit)
• UART (SPP or HCL) and USB (HCI only) data connection interfaces.
• Sustained SPP data rates: 240 Kbps (slave), 300Kbps (master)
• HCI data rates: 1.5 Mbps sustained, 2.0Mbps burst in HCI mode
• Bluetooth SIG certified
• Castellated SMT pads for easy and reliable PCB mounting
• Certifications: FCC, ICS, CE

Interface

1. xBee:
Communication setup:

Since we are not connecting the xBee directly to our computer to work on the configuration and we have to connect it through using the SJ One board with UART communication pins. Thus, we have to initially set the baud rate at 115200. On xBee chip set, there are 20 pins including VCC and GND. In our design of the communication bridge, we just need four of them including VCC (Pin1), GND(Pin10), Data Out(Pin2), and Data In (Pin3). For xBee chip set connected with Bluetooth module, VCC is connected to SJ One board VCC out as well as GND. For Data out on xBee, it is connected UART 2 Rx(Pin49) and Data in connected to UART Tx(Pin50). For xBee chip set connected to car SJ One board, we can directly place it on xBee connect pins on SJ One board.

Figurex: Pinout of xBee

Figurex: UART2 pins of SJOne Board

Pairing:

In order to let the xBee pair to communicate to each other, we have to set both xBee chip sets have the same PAN ID. The xBee has factory default setting that we just have to input default commands for viewing or changing the setting on chips. Some of major commands show as following:

Testing & Technical Challenges

Module Name	S.R.	Test Case	Test Description	Result
Sensor	1	-	-	-
	2	-	-	-
	3	-	-	-
Motor	1	-	-	-
	2	-	-	-
	3	-	-	-
I/O	1	-	-	-
	2	-	-	-
	3	-	-	-
Communication Bridge+ Android	1	-	-	-
	2	-	-	-
	3	-	-	-
Geographical	1	-	-	-
	2	-	-	-
	3	-	-	-
Master	1	-	-	-
	2	-	-	-
	3	-	-	-

Schedule

Sensor Team Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/14/2014	09/20/2014	Understanding the logic of sensors to be used	Completed	09/20/2014
2	09/21/2014	10/04/2014	Writing the codes for the different types of sensors	Completed	10/04/2014
3	10/05/2014	10/11/2014	Testing the different sensors for accuracy and placing the order for the one we have selected.	Completed	10/11/2014
4	10/12/2014	10/25/2014	Build CAN transceiver and send data to the Master Board	Completed	10/25/2014
5	10/26/2014	11/01/2014	Place all the sensors on car and test for obstacle avoidance	Completed	10/28/2014
6	11/02/2014	11/14/2014	Work on light and tilt sensors	Completed	11/04/2014
7	11/15/2014	12/09/2014	Final testing and debugging	Completed	12/19/2014

Motor Team Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/14/2014	09/20/2014	Understand the logic of Motor Controller present in the RC Car	Completed	09/20/2014
2	09/21/2014	09/27/2014	Replace on-board controller with SJSU One board	Completed	09/22/2014
3	09/28/2014	10/04/2014	Drive the DC motor with SJSU One board at different Duty Cycles	Completed	09/30/2014
4	10/05/2014	10/11/2014	Test the Servo and DC motor together for moving forward and taking turns	Completed	10/09/2014
5	10/12/2014	10/18/2014	Build CAN Transceiver and move the car as per the CAN message received	Completed	10/13/2014
6	10/19/2014	10/25/2014	Make arrangement for CAN subscription task	Completed	10/25/2014
7	10/26/2014	11/01/2014	Interface encoder and calculate the actual speed at which car is running	Completed	10/28/2014
8	11/02/2014	11/08/2014	Make compensation algorithm and make car to move at desired speed	Completed	11/04/2014
9	11/09/2014	12/09/2014	Final testing and debugging	Completed	12/19/2014

I/O Team Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/14/2014	09/20/2014	Search and order GLCD module with touch screen, LEDs for headlights	Completed	09/20/2014
2	09/21/2014	10/04/2014	Study of GLCD data frame formats and design GUI	Completed	10/03/2014
3	10/05/2014	10/11/2014	Development of GLCD functions including touchscreen handler	Completed	10/11/2014
4	10/12/2014	10/25/2014	Setup CAN subscription tasks for communication with Master controller	Completed	10/27/2014
5	10/26/2014	11/01/2014	Develop hardware and code for automatic headlight control.	Completed	11/01/2014
6	11/02/2014	11/14/2014	Build hardware for switches and write interrupt handlers for the same	Completed	11/07/2014
7	11/15/2014	12/09/2014	Mount GLCD, headlights, switches on car and final testing	Completed	12/19/2014

Communication Bridge + Android Team Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/14/2014	09/20/2014	Google maps API research	Completed	09/20/2014
2	09/21/2014	10/04/2014	Mock locations on Google maps and simulate co-ordinates w/o gps	Completed	10/04/2014
3	10/05/2014	10/11/2014	Two way Bluetooth communication and setup RTOS tasks	Completed	10/11/2014
4	10/12/2014	10/25/2014	Raw GUI for app and setup CAN tasks for Start and Stop commands	Completed	10/25/2014
5	10/26/2014	11/09/2014	Integration with GEO module and queue for each subscribed service	Completed	11/09/2014
6	11/10/2014	11/16/2014	Incorporate all essential services into Android app and test for response	Completed	11/16/2014
7	11/16/2014	11/23/2014	Final setup and changes for all the CAN tasks along with XBee interfacing	Completed	11/23/2014
8	11/24/2014	12/01/2014	Testing with GEO module with real-time co-ordinates and plotting way points onto Maps	Completed	12/01/2014
9	12/02/2014	12/09/2014	Final Testing and verification of all components on the main field	Completed	12/19/2014

GEO Team Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/7/2014	09/14/2014	Market research for GPS and Compass Modules	Completed	09/14/2014
2	09/14/2014	09/21/2014	Place order / receive the modules	Completed	09/20/2014
3	09/21/2014	09/28/2014	Interface GPS with SJ -One board via UART	Completed	09/26/2014
4	09/28/2014	10/05/2014	Interface Compass with SJ-One Board via I2C	Completed	10/03/2014
5	10/05/2014	10/12/2014	Parsing the GPS data stream	Completed	10/11/2014
6	10/12/2014	10/19/2014	Calibration and testing of compass	Completed	10/13/2014
7	10/12/2014	10/19/2014	Decide CAN message ID’s and message formats	Completed	10/28/2014
8	10/19/2014	10/26/2014	Combining UART and GPS parsing. Create task for GPS	Completed	10/25/2014
9	10/19/2014	10/26/2014	Combining compass calibration and i2c interface. Create task for Compass	Completed	10/25/2014
10	10/26/2014	11/02/2014	Distance to Destination Calculation and Algorithm	Completed	11/02/2014
11	11/03/2014	11/10/2014	Basic CAN communication with Master, IO and Android	Completed	11/10/2014
12	11/10/2014	11/17/2014	Synchronization and Data Integrity (Semaphores/Mutex/Critical Section)	Completed	11/17/2014
13	11/18/2014	11/25/2014	Final Integration of CAN Framework and Implementation of CAN communication with other modules	Completed	11/25/2014
14	11/26/2014	12/09/2014	Testing and debugging on car (Re-Calibration/Bug Fixes)	Completed	12/19/2014

Master Team Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/7/2014	09/13/2014	Understanding CAN Bus and API's	Completed	09/13/2014
2	09/14/2014	09/20/2014	Deciding System Flow	Completed	09/20/2014
3	09/21/2014	09/27/2014	Deciding MSG id's for all devices	Completed	10/27/2014
4	09/28/2014	10/11/2014	Testing Subscription between 2 devices	Completed	10/4/2014
5	09/28/2014	10/11/2014	Making CAN bus hardware to interface all SJOne boards	Completed	10/11/2014
6	09/28/2014	10/11/2014	Testing subscription and time sync between all devices	Completed	10/11/2014
7	10/12/2014	10/18/2014	Reading sensor data from boards at the subscription rate	Completed	10/26/2014
8	10/19/2014	11/1/2014	Algorithm for obstacle avoidance	Completed	10/27/2014
9	11/2/2014	11/15/2014	Algorithm for GPS based navigation	Completed	11/15/2014
10	11/16/2014	11/22/2014	Initial testing and tweaking of the car	Completed	11/22/2014
11	11/23/2014	12/9/2014	Final Testing! Showdown time!	Completed	12/19/2014

References

Acknowledgement

The hardware components were made available from Amazon, Sparkfun, Adafruit, HSC, Excess Solutions. Thanks to Preetpal Kang for providing right guidance for our project.

References Used

1. LPC_USER_MANUAL
2. Ultrasonic Sensor
3. ADC Sensor
4. GLCD with Touchscreen
5. XBee Module
6. Bluetooth Module
7. GPS Module
8. Compass Module
9. CAN Transceiver
10. Linear Voltage Regulator
11. Socialledge Embedded Systems Wiki
12. Preetpal Kang, Lecture notes of CMPE 243, Computer Engineering, Charles W. Davidson College of Engineering, San Jose State University, Aug-Dec 2014.
13. en.wikipedia.org/