Just L. Herder

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— To evaluate and optimize the mechanical design of underactuated hands, a benchmark test is defined that quantifies the ability to hold grasped objects subject to force disturbances as occurs during for instance pick and place operations. The ability to hold is quantified by the magnitude of the maximum permitted static force on the center of a cylindrical(More)
This paper investigates the possibility of converting grasped objects from precision grasps to power grasps using a variable transmission ratio for an underactuated finger. To this effect, a variable radius pulley was designed. A simulation study is presented to analyse grasping behaviour and a potential energy method is used to predict the equilibrium(More)
This article describes the development of a mobile arm support for people with muscular diseases. The arm support is spring-balanced, with special attention on reduction of operating effort (high balancing quality and low friction), functionality (large range of motion), and aesthetics (inconspicuous design). The spring settings can be adjusted for wearing(More)
Active movement-assistive devices aim to increase the quality of life for patients with neuromusculoskeletal disorders. This technology requires interaction between the user and the device through a control interface that detects the user’s movement intention. Researchers have explored a wide variety of invasive and non-invasive control interfaces. To(More)
increasing the robustness of underactuated grasping through the use of variable transmission ratios. We propose a 4-step procedure to investigate and improve the robustness of an underactuated finger on a fixed object. This procedure maximizes the robustness against random force disturbances to the maximum obtainable value under given circumstances. A(More)
— In this paper, we design, fabricate, and validate a large-stroke 3-degree-of-freedom (DOF) positioning stage with integrated displacement sensors for feedback control in a single-mask microelectromechanical systems (MEMS) fabrication process. Three equal shuttles exactly define the position of the stage in x, y, and R z. The kinematic relation between the(More)
The development of dynamic hand orthoses is a fast-growing field of research and has resulted in many different devices. A large and diverse solution space is formed by the various mechatronic components which are used in these devices. They are the result of making complex design choices within the constraints imposed by the application, the environment(More)
Persons suffering from progressive muscular weakness, like those with Duchenne muscular dystrophy (DMD), gradually lose the ability to stand, walk and to use their arms. This hinders them from performing daily activities, social participation and being independent. Wheelchairs are used to overcome the loss of walking. However, there are currently few(More)