Experimental and simulation studies of motion control of a Delta robot using a model-based approach

Abstract

Robot manipulators are mostly used to complete positioning tasks, and the conventional approach utilizes position-based control scheme, which converts a robot control problems to several motor control problems, where encoder signals are used to fulfill feedback control. This control scheme might not provide excellent positioning accuracy due to the lack of the dynamics of robot manipulators. This article presents a simple model-based control scheme to achieve the positioning control and applies the scheme to a Delta robot, which can perform the motion with three translational degrees of freedom. The proposed scheme first evaluates the applied torques of motors based on robot's kinematics and dynamics using the encoders, and then the evaluated torques are sent to controllers to fulfill feedback control. The entire control loop is little similar to torque control, but torque or current sensors are not used. To demonstrate the performances of the proposed scheme, not only the numerical simulations are performed but also the experimental work is conducted. Both results are compared with those by applying the position-based control. The results show that the proposed modelbased control scheme provides better positioning accuracy.

Verification of the UR5 robot’s properties after a crash caused by a fall of a transferred load from a crane

“…For example, elastokinematical models of manipulators are developed in 17 or. 18 Stiffness analysis allows designers and engineers to achieve the balance between dynamics and accuracy. 19 Nowadays, there are three basic methods dealing with the mentioned investigated issue, namely finite element analysis, matrix structural analysis and virtual joint modelling (VJM).…”

“…For example, elastokinematical models of manipulators are developed in 17 or. 18 Stiffness analysis allows designers and engineers to achieve the balance between dynamics and accuracy. 19…”

Design and Development of a Novel 2-Degree-of-Freedom Parallel Robot

“…Works related to the Delta robot are countless. [21][22][23] Among these, the work by Yang et al provided a nonspherical ball socket joint design. 24 They reconstructed a traditional spherical joint according to a quantitative analysis of the loading deflection and designed a nonspherical joint with nearly the same joint clearance in every direction.…”

Modelling and Path Planning of Delta Parallel Robot in Virtual Environment

“…The well-known Gough-Stewart platform with six degrees of freedom (dof) is analysed in [2] and for which the dynamic model is derived using technique of bond graphs. The most used configuration of the parallel robots are delta robots, which have two platforms, one fixed and joined to a moveable platform by three parallel chains [1], [7], [8], [9], [10], [12], [13], [14] and [15]. Kinematic consideration of the parallel robot is subject of [1], [12].…”