To address the complex challenge of identifying contact state between a shaft and hole to improve efficiency robotic shaft-hole assembly tasks, method based on variable admittance control is proposed. In this method, serves as foundational force controller for assembly. On basis, Twin Delayed Deep Deterministic policy gradient (TD3) algorithm from deep reinforcement learning utilized optimize parameters controller. Additionally, nonlinear reward function designed, which not only prevents...

This paper proposes an enhanced multi-strategy sparrow search algorithm to optimize the trajectory of a six-axis industrial robot, addressing issues low efficiency and high vibration impact on joints during operation. Initially, improved D-H parametric method is employed establish both forward inverse kinematic models robot. Subsequently, 3-5-3 mixed polynomial interpolation planning approach applied Building upon conventional algorithm, two-dimensional Logistic chaotic system initializes...

This paper proposes a novel calibration method for robot kinematic parameters by constraining command point. At first, the profile errors derived from measuring sphere surface laser displacement sensor are estimated and analyzed. A three-step measurement procedure is performed around point with only one single sensor. Then, error model including both parameter between base frame established. An identification algorithm comprising least square particle swarm optimization developed. Comparison...

Lightweight robotic arms are one of the main technologies to improve working performance in future. Focusing on spatial vibrations issue brought about by light-weighting a space arm this paper, rigid–flexible coupling dynamics model system was established based assumed mode method and Lagrange method. Based lightweight flexible structure, comparative analysis first four functions conducted under different fixed constraints physical properties determine order that matches simulation arm,...

Purpose In typical model-based calibration, linearization errors are derived inevitably, and non-negligible negative impact will be induced on the identification results if rotational kinematic not small enough or lengths of links too long, which is common in industrial cases. Thus, an accurate two-step calibration method minimizing presented for a six-DoF serial robot to improve accuracy. Design/methodology/approach The accuracy minimized by removing responsible linearized from complete...

SUMMARY In typical calibration methods (kinematic or non-kinematic) for serial industrial robot, though measurement instruments with high resolutions are adopted, configurations optimized, and redundant parameters eliminated from identification model, accuracy is still limited under noise. This might be because huge gaps exist among the singular values of Jacobians, thereby causing models ill conditioned. paper addresses such problem by using new established in two steps. First, divided into...

Traditional mobile robots have limited mobility in complex terrain environments. Generally, the closed-chain leg structure of a foot-type robot relies on speed difference to turn, but it is difficult complete turning action narrow spaces. Therefore, this study proposes that can move multiple directions, inspired by WATT-I structure. Firstly, single-leg designed, and analyzed terms degrees freedom, kinematics, singularity. A simulation also carried out. Secondly, based present trajectory,...

Drilling of a bone surface often occurs in clinical orthopaedic surgery. The position and orientation the instrument are most important factors this process. Theoretically, some mechanical components may assist orienting an to certain shapes, such as knee joint caput femoris. However, assisting component does not seem work confined spaces where shape is free-form surface. In paper, we propose ingenious hemisphere tabulation method (HTM) for assessing pose accuracy instrument. acquisition...

As an example of a minimally invasive arthroscopic surgical procedure, osteochondral autograft transplantation (OAT) is common option for repairing focal cartilage defects in the knee joints. Arthroscopic OAT offers considerable benefits to patients, such as less post-operative pain and shorter hospital stays. However, performing arthroscopically extremely demanding task because graft harvester must remain perpendicular surface avoid differences angulation.We present practical ArthroNavi...

Summary This paper investigates the finite time stabilization problem for a class of nonlinear systems with unknown control directions and unstructured uncertainties. The uncertainties indicate that not only parameters but also structure system nonlinearities are uncertain. A new adaptive method is proposed considered system. Logic‐based switching rule utilized to tune controller online stabilize in time. Different from existing controllers structured/parametric uncertainties, barrier...