Modeling and Control of a New Narrow Vehicle

Traffic problems such as pollution and congestion are becoming ever more serious in urban areas. A potential solution to these problems may be the development of narrow vehicles, which occupy less space and produce fewer gas emissions. There has been increasing interest in these types of underactuated mechanical systems, such as Mobile Wheeled Inverted Pendulum (MWIP) models, which are widely used in the field of autonomous robotics and intelligent narrow vehicles. A novel structure based on an MWIP and a movable seat above called the UW-Car is investigated in this study. Dynamic models of this underactuated vehicle running on flat ground and in rough terrain are derived using Lagrange's motion equation. Based on the models and the Terminal Sliding Mode Control (TSMC) method, two terminal sliding mode controllers were designed for the velocity and braking control of a UW-Car. The first one is for heading speed to a set-point while keeping the body upright and the seat in some fixed position. The second one is a switching sliding mode controller made up of three terminal sliding mode controllers. By using the proposed controller, a UW-Car can move at a desired velocity while keeping the seat always upright. To solve the problem of obtaining quick acceleration performance in a UW-Car, a control method combining trajectory generation and dynamics canceling inputs is proposed. Using this method, the UW-Car can achieve high acceleration while keeping its body upright at all times. All the proposed theoretical results are finally demonstrated through numerical simulations.