20,673 research outputs found
Learning Task Constraints from Demonstration for Hybrid Force/Position Control
We present a novel method for learning hybrid force/position control from
demonstration. We learn a dynamic constraint frame aligned to the direction of
desired force using Cartesian Dynamic Movement Primitives. In contrast to
approaches that utilize a fixed constraint frame, our approach easily
accommodates tasks with rapidly changing task constraints over time. We
activate only one degree of freedom for force control at any given time,
ensuring motion is always possible orthogonal to the direction of desired
force. Since we utilize demonstrated forces to learn the constraint frame, we
are able to compensate for forces not detected by methods that learn only from
the demonstrated kinematic motion, such as frictional forces between the
end-effector and the contact surface. We additionally propose novel extensions
to the Dynamic Movement Primitive (DMP) framework that encourage robust
transition from free-space motion to in-contact motion in spite of environment
uncertainty. We incorporate force feedback and a dynamically shifting goal to
reduce forces applied to the environment and retain stable contact while
enabling force control. Our methods exhibit low impact forces on contact and
low steady-state tracking error.Comment: Under revie
Real-Time Motion Planning of Legged Robots: A Model Predictive Control Approach
We introduce a real-time, constrained, nonlinear Model Predictive Control for
the motion planning of legged robots. The proposed approach uses a constrained
optimal control algorithm known as SLQ. We improve the efficiency of this
algorithm by introducing a multi-processing scheme for estimating value
function in its backward pass. This pass has been often calculated as a single
process. This parallel SLQ algorithm can optimize longer time horizons without
proportional increase in its computation time. Thus, our MPC algorithm can
generate optimized trajectories for the next few phases of the motion within
only a few milliseconds. This outperforms the state of the art by at least one
order of magnitude. The performance of the approach is validated on a quadruped
robot for generating dynamic gaits such as trotting.Comment: 8 page
Practice of law in the provisioning of accessibility facilities for person with disabilities in Malaysia
Malaysia’s significant changes can be seen clearly through the improvement of social welfare of the disabled and people with disabilities. Although the governments has carried out various policies and provide facilities as well as provision for the disabled but there are still many obstacles encountered by people with disabilities, especially the legal and the accessibility of facilities and services. Therefore, this paper attempts to discuss the practice of law relating of legal procedure particularly for disabled users which affects the movement of these people from one destination to another. This paper discusses the practice of law adopted in the preparation of facilities for disabled people to help them make movement independently. The study was conducted by secondary data to the Malaysia legal and policies for disabled person by comparing with United Kingdom (UK). Malaysia has come out with a strong legal framework for disabled person through People with Disabilities Act 2008 (Act 685). There are several areas in the act that still can be improved to support disabled person
- …