A Hybrid Robust Lyapunov Controller for Dynamic Catch, Grasp and Carry Maneuvers

A hybrid Lyapunov based controller for dynamic catch, grasp, and carry tasks of grippers is developed. The Lyapunov controller unifies the trajectory planning and tracking tasks in one, and neither a separate trajectory planning algorithm is needed to run offline nor any type of learning process. The robustness of the controller is demonstrated, through simulations with inertial parametric uncertainties. The concept is presented with the simulations of six degrees-of-freedom (DOF) double revolute (RR) planar manipulator with a 4DOF gripper and a 8DOF triple revolute (RRR) manipulator with a 5DOF gripper.

A Lyapunov controller for self-balancing two-wheeled vehicles

SUMMARYSegway is a self-balancing motorized two-wheeled vehicle which is able to carry the human body. The main issue in design of such a vehicle is to choose a stable control system capable of keeping the rider close to the upright position over smooth and non-smooth surfaces. This work extends the research previously performed by the authors for design of a controller, using the feedback linearization technique, to increase the stability of a two-wheeled vehicle carrying human. This paper investigates the design and validation of a controller for an inertial mobile vehicle using the Lyapunov's feedback control design technique. The system equations of motion are derived followed by finding the Lyapunov function required to design the controller. Owing to the discontinuity, originating from a sign function in the control law, the proposed control system is discontinuous. Therefore, the existence, continuity, and uniqueness of the solution are proven utilizing the Filippov's solution. Afterwards, the asymptotic stability of the control system is proven using the extensions of Lyapunov's stability theory to nonsmooth systems, and LaSalle's invariant set theorem. Finally, the effectiveness of the proposed control system is validated using simulation studies. Results confirm that the controller keeps the system stable while provides good position tracking responses.

Vibration Control of Buildings Using Magnetorheological Damper: A New Control Algorithm

This paper presents vibration control of a building model under earthquake loads. A magnetorheological (MR) damper is placed in the building between the first floor and ground for seismic response reduction. A new control algorithm to command the MR damper is proposed. The approach is inspired by a quasi-bang-bang controller; however, the proposed technique gives weights to control commands in a fashion that is similar to a fuzzy logic controller. Several control algorithms including decentralized bang-bang controller, Lyapunov controller, modulated homogeneous friction controller, maximum energy dissipation controller, and clipped-optimal controller are used for comparison. The new controller achieved the best reduction in maximum interstory drifts and maximum absolute accelerations over all the control algorithms presented. This reveals that the proposed controller with the MR damper is promising and may provide the best protection to the building and its contents.

Field-programmable gate array controller design for air-powered motorcycle

This article presents a field-programmable gate array (FPGA) speed controller design and applied in an air-powered motorcycle which utilizes an air motor and a high-pressure gas cylinder to replace the internal combustion engine and oil tank, respectively. One of the main purposes of this research is to find the relationship between velocity and efficiency of an air-powered motorcycle. In addition, a speed control system is developed based on FPGA in order to control the velocity of an air-powered motorcycle. The control theories are actualized by the hardware description language and modular conception is used to divide a complex system into many parts. This design methodology shortens the development time and is easy to modify for each module. Besides, the system dynamics of air-powered motorcycle was derived through the tractive effort and the dynamic response was simulated by the Matlab software. From the experimental results, the air-powered motorcycle can drive with the best efficiency, at the velocity expected by the proportional–integral (PI) and Lyapunov speed controllers. Also, the experimental data show that the chattering ranges are 2.7 per cent and 6.9 per cent of Lyapunov controller and PI controller, respectively, under the same velocity.