Search

This paper presents a transformable track mechanism for wall climbing robots. The proposed mechanism allows a wall climbing robot to go over obstacles by transforming the track shape, and also increases contact area between track and wall surface for safe attachment. The track mechanism is realized using a timing belt track with one driving actuator. The inner frame of the track consists of serially connected 5R-joints and 1P-joint, and all joints of the inner frame are passively operated by springs, so the mechanism does not require any actuators and complex control algorithms to change its shape. Static analysis is carried out to determine design parameters which enable 90o wall-to-wall transition and driving over projected obstacles on wall surfaces. A Prototype is manufactured using the transformable track on which polymer magnets are installed for adhesion force. The size of the prototype is 628mmⅩ200mmⅩ150mm (LengthⅩWidthⅩHeight) and weight is 4kgf. Experiments are performed to verify its climbing capability focusing on 90o wall to wall transition and driving over projected obstacle.

Recent research on mobile robots has focused on locomotion in various environments. In this paper, a gait-generation algorithm for a mobile robot that can travel from the ground to a wall and climb vertical surfaces is proposed. The algorithm was inspired by a gecko lizard. Our gait planning was based on inverse kinematics using the Jacobian of the whole body, where the redundancy was solved by defining an object function for the gecko posture to avoid collisions with the surface. The optimal scalar factor for these two objects was obtained by defining a superior object function to minimize the angular acceleration of joints. The algorithm was verified through simulation of the gecko model travelling on given task paths and avoiding abnormal joint movements and collisions.

This paper presents a redundantly actuated six degrees-of-freedom parallel kinematic mechanism with a partially decoupled architecture in its rotational motion. This mechanism is developed to eliminate kinematic complexity of original Eclipse-II known as a redundant parallel mechanism. Since the original Eclipse-II mechanism use kinematic redundancy of parallel mechanism to achieve an advantage in enlarging the workspace of the system, it needs a motion planning algorithm to choose the specific control inputs to determine the desired motion trajectory. This motion planning algorithm causes difficulty in achieving real-time control performance due to its structural complexity. However the redundant parallel mechanism presented in this paper is a redundant parallel mechanism with partially decoupled architecture in its rotational motion. Therefore modified Eclipse-II redundant parallel mechanism can realize effective real-time control performances and continuous 360-degree rotational motion in any direction of the moving platform with six degrees of freedom.

This paper presents a kinematic analysis of the locomotion of a gecko, and experimental verification of the kinematic model. Kinematic analysis is important for parameter design, dynamic analysis, and optimization in biomimetic robot research. The proposed kinematic analysis can simulate, without iteration, the locomotion of gecko satisfying the constraint conditions that maintain the position of the contacted feet on the surface. So the method has an advantage for analyzing the climbing motion of the quadruped mechanism in a real time application. The kinematic model of a gecko consists of four legs based on 7-degrees of freedom spherical-revolute-spherical joints and two revolute joints in the waist. The motion of the kinematic model is simulated based on measurement data of each joint. The motion of the kinematic model simulates the investigated real gecko’s motion by using the experimental results. The analysis solves the forward kinematics by considering the model as a combination of closed and open serial mechanisms under the condition that maintains the contact positions of the attached feet on the ground. The motions of each joint are validated by comparing with the experimental results. In addition to the measured gait, three other gaits are simulated based on the kinematic model. The maximum strides of each gait are calculated by workspace analysis. The result can be used in biomimetic robot design and motion planning.