This work describes a new human-in-the-loop (HitL) assistive grasping system for individuals with varying levels of physical capabilities. We investigated the feasibility of using four potential input devices with our assistive grasping system interface, using able-bodied individuals to define a set of quantitative metrics that could be used to assess an assistive grasping system. We then took these measurements and created a generalized benchmark for evaluating the effectiveness of any arbitrary input device into a HitL grasping system. The four input devices were a mouse, a speech recognition device, an assistive switch, and a novel sEMG device developed by our group that was connected either to the forearm or behind the ear of the subject. These preliminary results provide insight into how different interface devices perform for generalized assistive grasping tasks and also highlight the potential of sEMG based control for severely disabled individuals.
@cite_5: In this paper, we propose a mathematical framework which formalizes user-driven customization of shared autonomy in assistive robotics as a nonlinear optimization problem. Our insight is to allow the end-user, rather than relying on standard optimization techniques, to perform the optimization procedure, thereby allowing us to leave the exact nature of the cost function indeterminate. We ground our formalism with an interactive optimization procedure that customizes control sharing using an assistive robotic arm. We also present a pilot study that explores interactive optimization with end-users. This study was performed with 17 subjects (4 with spinal cord injury, 13 without injury). Results show all subjects were able to converge to an assistance paradigm, suggesting the existence of optimal solutions. Notably, the amount of assistance was not always optimized for task performance. Instead, some subjects favored retaining more control during the execution over better task performance. The study supports the case for user-driven customization and provides guidance for its continued development and study.
@cite_4: We present a mobile manipulation platform operated by a motor-impaired person using input from a head-tracker, single-button mouse. The platform is used to perform varied and unscripted manipulation tasks in a real home, combining navigation, perception and manipulation. The operator can make use of a wide range of interaction methods and tools, from direct tele-operation of the gripper or mobile base to autonomous sub-modules performing collision-free base navigation or arm motion planning. We describe the complete set of tools that enable the execution of complex tasks, and share the lessons learned from testing them in a real user's home. In the context of grasping, we show how the use of autonomous sub-modules improves performance in complex, cluttered environments, and compare the results to those obtained by novice, able-bodied users operating the same system.
Not only is the form of input into the system important, but so is the design of the interface. Much work and care must be put into making sure the system is robust to user input and also allows the user to accurately see what is happening in the environment as a result of the system @cite_4 . Because HitL software is so focused on getting accurate input from the user, there is not much room for ambiguity @cite_5 .