In this paper, we propose an adaptive controller for virtual passive biped dynamic walking on unknown uneven terrain. The adaptive controller consists of a trajectory tracking control law developed via backstepping method to mimic reference passive gait, and a slope estimator for the inclination angle of the terrain. In addition, a re-planning approach is introduced to correct the robot state off-track from the reference gait due to the terrain changes. The controller is validated through the simulations on the mixed uneven terrain consisting of varying slopes and steps. The results suggest that the controller shows comparable cost of transport and greater adaptability to terrain changes compared with certain existing methods.

It is well known a fine tuned unpowered biped machine can passively walk down a gentle slope. The in-depth understanding of the passivity is helpful to design more efficient bipedal gaits. In this paper, we investigate the principle mechanism of passive dynamic walking and propose a unified framework for virtual passive bipedal gait generation. The framework shows the physical system's kinetic energy varies inversely proportional to the imitated virtual system's potential energy. Based on this property we propose a kinetic energy tracking control law to realize virtual passive dynamic walking on any slopes in any virtual gravity fields. Numerical simulations are given to support our proposal.

A new golf swing robot performing high-speed golf swings has been developed by the authors. This paper deals with the motion planning problem of the golf swing. At first, the reverse time symmetry and single pendulum inherences in manipulator dynamics are introduced. Then, by utilizing the first inherence, the Rest-to-Point motion planning problem for the backswing and downswing is transformed into a reverse time symmetric Point-to-Rest motion planning problem. Finally, based on the second inherence, a Proportional plus Gravity and Coupling Torque Compensation (PGCTC) control scheme is developed to solve both the reverse time symmetric Point-to-Rest motion planning problem for the backswing and downswing and the forward time Point-to-Rest problem for the follow-through. Simulation shows the effect of the proposed method.

This paper reports a motion planning scheme for a high performance robot aiming to realize the motion control skills exhibited by professional golfers. The robot has a dexterous mechanism with similar distribution of actuators' capability and a pair of mechanical joint stops like human beings. The proposed motion planning method combines target dynamics together with port-controlled Hamiltonian (PCH) system theory resulting in an energy controller which not only takes the mechanical joint stops into account but also realizes torque compensation from a high-power actuator to a low-power actuator. Simulation and experimental results prove the proposed method can generate the golf swings with specified hitting speed and finish position for our specially designed robot.

A new golf swing robot performing high-speed golf swings has been developed by the authors. This paper deals with the motion planning problem of the golf swing. A target dynamics based control scheme is proposed. This control scheme maps the robot to a harmonic oscillator (target dynamical system). Based on the target system, energy control is adopted to realize a specified hitting speed at a specified impact position in the swing. After the swing passed through the impact position, PD control and PD plus gravity, joint torque and coupling torque compensation control are adopted to smoothly slow down and stop the swing at a specified finish position. Simulation and experimental results show the effect of the proposed method