Motorbike ESC: Active Stability Control with ABS and Crash Location Sensing without GPS for E-Bicycles Motivation:

Motorbike ESC: Active Stability Control with ABS and Crash Location Sensing without GPS for E-Bicycles
Motivation:
E-Bicycles promises to be the future of two wheeled motor cycles in the coming decades because the world wants to become greener and free from pollution. We feel the present day safety features integrated within these two wheeled vehicles are inadequate and so we turned to technology to look for ways to make the e-bicycle riding into a much safer experience.
Introducing ABS and ESC:
One important safety technology used in high end cars and trucks is called ABS (Anti-Lock Braking System) which has already become a mandatory feature for vehicles in US and Europe. But first…What is the thing called ABS? ABS is an electro-mechanical system that helps reduce wheel skid in automobiles by controlling the brake force applied to each wheel, making it easier to stay in control while riding. ABS equipped bicycles are still evolving.
Active Stability Control or Electronic Stability Control (ESC) is a safety feature that improves the vehicle stability by sensing yaw rate and roll rate inorder to improve steering control in four-wheeled vehicles. It was introduced to improve passengers’ safety in critical driving conditions such as cornering or sudden obstacle avoiding manure. This system uses the ABS at its heart for its longitudinal braking
control and senses vehicle dynamics and drivers intention in order to stabilize the vehicle by avoiding rolling, skidding and loss of traction.
Thus the equation stands like this
Active Stability Control = ABS + Vehicle Dynamics Sensors + Driver Steering Sensors
Problem Description and Our Solution:
Although ABS for two wheeled vehicles are available, the design of a two wheeled vehicle stability control system constitutes quite a challenging task due to the complexity of two-wheeled vehicles dynamics and to the strong interaction between the vehicle and the driver. For this reason, there is no solution commercially available for two wheeled vehicles that have an active stability control system.
But in countries like India, two wheeled vehicles are substantially more than their four wheeled counterpart. Hence we are proposing a project that designs an innovative control architecture which allows us to enhance the active safety and stability of the vehicle while guaranteeing a good driving feeling.
Abstract:
Our project aim is to
 Design an advanced electronic active stability control system with ABS assistance for e-bicycles providing the much needed vehicle roll stability control in situations such as high speed cornering etc..,
 Design a system that, in case of an emergency situation such as crashing, will send the bicycle accident location to nearby hospitals/emergency services without the assistance of costlier GPS tracking systems.
Detailed Description:
Active Stability Control system takes multiple sensor inputs to find the optimal braking force to be applied. The system measures the force applied to the front and rear wheel brake levers, the angle of the vehicle, driver steering angle, driver accelerator input along with the wheel speed in order to calculate the braking force. If it detects a vehicle skid situation or vehicle roll situation or wheel lock-up on one or both wheels, the controller calculates the braking pressure needed for each wheel and applies it differentially to them using electrical motors, counteracting the rider’s squeezing force on the levers. Adjustment Keypad allows the rider to set the skid threshold level at which the system activates, allowing for different performance characteristics depending on the trail surface. Vehicle dynamics is sensed using the 6-DOF Digital MEMS Compass module that integrates a 3-axis MEMS Magnetometer and a 3-axis MEMS Accelerometer.
Vehicle location tracking system reads the Digital MEMS Compass module that will be used for tracking the vehicle without GPS. During a crash situation, sensed via the 3-axis MEMS Accelerometer,
the system automatically sends an emergency message using GSM to home/hospital/emergency services with embedded vehicle location data.
The entire system has three ECU (Electronic Control Unit) interconnected with each other. Couple of ECUs dedicated for individual front and rear wheel control. The wheels are controlled by two DC Motors, one for front and the other rear side. The ECU interfaces with Rotary Encoders to measure the speed and direction of the wheels. The third ECU is the dashboard unit. It interfaces with driver input sensors such as brake lever position sensors, accelerator position sensor and steering wheel position sensor. It is also interfaced with a Graphics LCD that acts as front dashboard display and provides a GUI to monitor the vehicle status. MEMS compass is connected to this unit.
All three ECU are connected with each other over the most popular vehicular network called CAN (Controller Area Network). CAN is an event-driven protocol that is very reliable for automotive applications. To meet the real-time deadlines, and to make the system robust, the software runs under FreeRTOS, the most popular open source real-time kernel in the world.
Each ECU is built around a 32-bit ARM Cortex-M0 microcontroller, LPC11C14 from NxP Semiconductors.
Software Tools Used:
 Programming Language: Embedded C
 Development Tool: LPCXpresso IDE (Eclipse based)
Embedded Protocols Used:
 I2C, SPI, UART, CAN.
Software Libraries Used:
 Graphics Library
 CAN Protocol Software Stack
 FreeRTOS Kernel Library
 Digital MEMS Compass Driver via I2C protocol
 GSM Modem Driver Software via UART protocol
 Cortex-M0 Peripheral Device Driver Library
 CMSIS from ARM
Project Advantages:
 Vehicle stability control is not available in two wheelers. This project is one of the first attempts.
 Less costly vehicle tracking system without GPS module.
 Electronic ABS control is superior to the currently available mechanical models.
 Less wire harness with the use of CAN communication network.
 Efficient real-time operation with the use of RTOS kernel in the main dashboard ECU.
 ARM Cortex-M0 microcontroller with inbuilt CAN controller provides a next generation hardware platform, ideal for networking ECU’s in E-bicycles.
 6-Axis MEMS Digital compass is an accurate tilt compensated direction sensor that provides the 360 degree direction by sensing the earth magnetic field orientation.
Stopping Distance Reduced
Sudden Braking Slippery Surface Braking