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This paper presents the direct-drive position control verification of a spiral motor in monoarticular configuration. The spiral motor is a newly developed high-thrust high-backdrivable direct-drive three-phase permanent-magnet motor with a unique 3-D structure. One of the possible uses of the spiral motor is to actuate musculoskeletal-like structure which is shown in animals and humans. This is achieved by indirectly actuating the elbow/shoulder joints via pulling/pushing the links by using a linear actuator. We describe the control methods for the direct drive of the spiral motor which are the decoupling control and independent control. Next, simulations were performed to assess the control parameter variation effects. Then, the experimental results confirm the validity of the control method in monoarticular position. The key element of the linear motion control of the spiral motor is the magnetic levitation (air gap between the stator and rotor) control and simultaneous angular motion control via vector d-and q-axis currents.

A new design method to obtain walking parameters for a three-dimensional (3D) biped walking along a slope is proposed in this paper. Most research is focused on the walking directions when climbing up or down a slope only. This paper investigates a strategy to realize biped walking along a slope. In conventional methods, the centre of mass (CoM) is moved up or down during walking in this situation. This is because the height of the pendulum is kept at the same length on the left and right legs. Thus, extra effort is required in order to bring the CoM up to higher ground. In the proposed method, a different height of pendulum is applied on the left and right legs, which is called a dual length linear inverted pendulum method (DLLIPM). When a different height of pendulum is applied, it is quite difficult to obtain symmetrical and smooth pendulum motions. Furthermore, synchronization between sagittal and lateral planes is not confirmed. Therefore, DLLIPM with a Newton Raphson algorithm is proposed to solve these problems. The walking pattern for both planes is designed systematically and synchronization between them is ensured. As a result, the maximum force fluctuation is reduced with the proposed method.

This paper presents the workspaceltaskspace control of a planar biarticular robot manipulator with linear actuation.Due to the nature of the biarticular structure, the configuration is closed link and has to include the constraints of the system. This paper presents the modelling of the planar structure and the simulation of workspace control by two methods, inverse kinematics and direct cartesian control using simplified inertia terms. Comparison is then done between the two methods to conclude the advantages and disadvantages. A significant finding is that by using the simplified two-link planar terms on the complex structure, control is achieved and improved.