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.
In the realm of micro- and nanomachining, high-precision three-dimensional miniaturized components and microstructures from an extensive range of engineering materials are increasingly required in industries such as optics, automotive, medical, aerospace, and defence. Five-axis ultraprecision micromilling machines are essential for manufacturing components and microstructures for these industries. This paper presents the design and development of the control system for a five-axis ultraprecision micromillling machine – Ultra-Mill – and its performance assessment based on two application case studies. The design specifications of Ultra-Mill are based on motion and positioning accuracy, dynamic stiffness, thermal stability, and online monitoring and inspection requirements, which are heavily dependent on the control system for the micromilling machine and associated micromilling processes. The implementation and application perspectives of the control system are therefore presented in relation to the ultraprecision and micro/nano feature capability of the machine and process, including controller dynamics, driver and actuation dynamics, feedback dynamics, online inspection and monitoring, and software dynamics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.