Implementation of Low-Level Control inAutonomous Ground Vehicle

The goal of this paper is to compute odometry of vehicle using low-level controls combined with inertial measurement unit.The Low-Level control includes design of Drive-by-Wire mechanisms for steering, brake and accelerator systems with appropriate motors and encoder.Experimentation with encoders and DC motors of steering and brake has been carried out first with various embedded modules to choose best suitable module.The experimentation has led to choosing BeagleBone Black (BBB), A lowcost, open-source community-supported development platform for real-time analysis provided by the TI Sitara AM3358 ARM Cortex-A8 processor with Linux-based operating system.Using BBB dedicated hardware module for high CPR (Counts per Revolution) encoders, the vehicle position is evaluated.Using BBB serial cape, it is interfaced to Roboteq motor controller (used for steering and brake motor) and steering encoder for steering wheel position control.The major task of the paper is the evaluation of odometry from using vehicle rear wheel encoders combined with inertial measurement unit.The paper is carried out on a dune buggy; petrol powered motor vehicle with Ackermann drive platform type and mobility.Initially, Drive-by-wire mechanism for steering, brake and accelerator is designed.Autonomous steering control of vehicle is carried out with feedback from steering motor encoder and steering hand wheel encoder connected to axle of steering system.Using IMU (Inertial Measurement Unit) yaw angle and rear wheel axle encoder position value, the odometry of vehicle are computed.Combined with inertial measurement units, they have proven to be a precise and low-cost sensor for vehicle odometry evaluation.