Expression of a Real Matrix as a Difference of a Matrix and its Transpose Inverse

In this paper we derive a representation of an arbitrary real matrix M as the difference of a real matrix A and the transpose of its inverse. This expression may prove useful for progressing beyond known results for which the appearance of transpose-inverse terms prove to be obstacles, particularly in control theory and related applications such as computational simulation and analysis of matrix representations of articulated figures.

A Review on Human Motion Prediction in Sit to Stand and Lifting Tasks

Human-like motion prediction and simulation is an important task with many applications in fields such as occupational-biomechanics, ergonomics in industrial engineering, study of biomechanical systems, prevention of musculoskeletal disorders, computer-graphics animation of articulated figures, prosthesis and exoskeletons design as well as design and control of humanoid robots, among others. In an effort to get biomechanical insight in many human movements, extensive work has been conducted over the last decades on human-motion prediction of tasks as: walking, running, jumping, standing from a chair, reaching and lifting. This literature review is focused on the STS motion and the LLM. STS is defined as the process of rising from a chair to standing up position without losing stability balance, it is the most ubiquitous and torque-demanding daily labor and it is closely related to other capabilities of the human body. LLM is defined as the activity of raising a load, generally a box, from a low to a higher position while stability is maintained, this task produces a high number of incidences of low-back pain and injuries in many industrial and domestic activities. In order to predict STS and LLM, two methods have been identified: these are the OBMG method and the CBMG method.

A general on-the-fly algorithm for modifying the kinematic tree hierarchy

A general on-the-fly algorithm for modifying the kinematic tree hierarchyWhen conducting a dynamic simulation of a multibody mechanical system, the model definition may need to be altered during the simulation course due to, e.g., changes in the way the system interacts with external objects. In this paper, we propose a general procedure for modifying simulation models of articulated figures, particularly useful when dealing with systems in time-varying contact with the environment. The proposed algorithm adjusts model connectivity, geometry and current state, producing its equivalent ready to be used by the simulation procedure. Furthermore, we also provide a simple usage scenario—a passive planar biped walker.