Conventional methods of balancing a bicycle, which exhibits stability and behavior similar to that of an inverted pendulum, involves implementation of complex control systems and hence is difficult to achieve. It leads to increased complexity of the system as well as the cost. However, this paper presents a method to attain the same with ease using a mechanically implemented control system which stabilizes the roll of the system. The research focuses on the novel system design to achieve the stability mechanically and to convert the bicycle into a drive by wire system with proper modifications to the braking and driving. The uniqueness of the design is that the bicycle doesn’t lose its normal operation and can be operated in a dual locomotion mode. Autonomous Navigation of the bicycle was achieved by localizing it with respect to its initial position and using global positioning system (GPS) for intelligent maneuvering by responding to the GPS coordinates of the destination received via SMS. The bicycle detects the obstacles in its path using laser and sonar based sensors and uses these data to appropriately plan its motion. The proposed product could find wide end to end applications such as autonomous parking and retrieval of bicycle to the users’ location, sharing between multiple persons. Also, with further modifications the technology can be transferred to motor bikes and autonomous navigation could be achieved. The dual locomotion mode added to the low cost and less complexity of the autonomous bicycle make this a viable product.
Modeling and Control of an Autonomous Three Wheeled Mobile Robot with Front Steer
Modeling and control strategies for a design of an autonomous three wheeled mobile robot with front wheel steer is presented. Although, the three-wheel vehicle design with front wheel steer is common in automotive vehicles used often in public transport, but its advantages in navigation and localization of autonomous vehicles is seldom utilized. We present the system model for such a robotic vehicle. A PID controller for speed control is designed for the model obtained and has been implemented in a digital control framework. The trajectory control framework, which is a challenging task for such a three-wheeled robot has also been presented in the paper. The derived system model has been verified using experimental results obtained for the robot vehicle design. Controller performance and robustness issues have also been discussed briefly.