This paper presents a novel six-degree-of-freedom (6-DOF) parallel platform that is used as the third mirror adjustment system of large space telescope. In order to meet design requirements high precision, load–size ratio, and stiffness in both transverse vertical directions, designed be 6-P-RR-R-RR structure via use offset RR-joints. The inverse kinematics problem with RR-joints much more complicated than common universal joints owing presence joint-dependent variables former problem. this...

The Gough-Stewart platform has been successfully used in a wide variety of fields ranging from medical to automotive applications. This paper proposes 6-RR RPRR parallel manipulator with orthogonal non-intersecting RR-joint configurations and ball screw actuators without guide mechanisms. A novel methodology is developed define the dependent variables numerical algorithm employed calculate joint variables. parasitic motion caused by helical can be expressed solved vector method. inverse...

This paper presents a kinematic calibration of 6-RRRPRR parallel mechanism with offset RR-joints that would be applied in space positioning field. In order to ensure highly accurate and effective process, the complete error model, which contains universal joint errors, is established by differentiating inverse model. A simulation comparison non-complete model shows errors are crucial improve accuracy. Using an optimal configuration selection algorithm developed determine least number...

This paper presents a new 6-DOF secondary mirror alignment mechanism for space optical payload. The moving platform is connected to the base by six PSS (Prismatic-Spherical-Spherical) serial chains. model established and inverse kinematics, Jacobian stiffness modeling are also performed. numerical simulation carried out verify proposed kinematics. prototype has been developed basic experiment which simulated Finally, requirements of accuracy, lateral natural frequency tested feasibility...

Due to the micro-vibration of flywheels, imaging quality a high-resolution optical remote sensing satellite will be deteriorated, and effect on payload is complicated, so it essential establish reasonable accurate theoretical simulation model for it. This paper presents method full-closed-loop time-domain integrated modeling estimate impacts generated by flywheels satellites. The consists three parts. First, according satellites’ influence mechanism in orbit, this establishes framework....

Abstract In order to improve the operational accuracy of microsurgical instruments and increase success rate surgery, a six-degree-of-freedom instrument is designed analyzed based on rigid-flexible coupling multi-body system. First, an improved kinematic modeling method proposed pseudo-rigid body theory. Second, simulation system built analyze error sources in terms remote center motion, preload, side load. Then, function motion scaling, modeling, validity workspace are demonstrated by...

In order to solve the uniqueness of compliance equations and each notch profile, a curvature-adjustable multiple-axis flexure hinge with complex profiles is designed investigated based on Bézier curve in this paper. The can evolve into hinges single hybrid, symmetric asymmetric composed ellipse, circle, hyperbola parabola. addition, analytical six degrees freedom Castigliano’s Second Theorem are proposed. Then, simplified profile classification method binary quadratic implicit equation...

Abstract A parameter‐space‐based robust platooning controller for the event‐triggered heterogeneous platoon is presented. The novel established with different longitudinal vehicle dynamic and driving preferences communication scheme designed to reduce utilization of resources. To handle stricter demand system disturbance caused by scheme, parameter space approach adopted optimize gains a controller. feasible region where internal stability string are satisfied then visualized in parameters...

This paper explores the enhancement of active suspension systems in vehicles, focusing on improving stability and passenger comfort under varying road conditions. We introduce Soft Actor-Critic (SAC) algorithm, a sophisticated reinforcement learning method, to advance efficiency responsiveness automobile systems. SAC is adeptly tailored navigate complex dynamics vehicle suspension, offering an intelligent alternative traditional control strategies. Our experimental results demonstrate...

A six degrees-of-freedom parallel platform in a 6-RR-RP-RR configuration with high accuracy, stiffness and large working stroke is studied for application to the sub-mirror adjustment system of large-aperture telescope. To meet performance requirements, adopts self-centering well-designed offset universal hinge. The two hinge axes do not intersect but have specific space, which makes kinematics more complex than that common Therefore, solve this problem, paper innovatively introduces...

When photoelectric measuring equipment is used to track satellites, the extraction of short-term or long-term target often fails because weak, clouds block target, and/or sun’s angle too small, resulting in loss tracking target. In this study, an improved Laplacian satellite method based on Kalman filter proposed. Firstly, algorithm was for initial fitting equation motion a small amount measurement data. Judgment validity and filtering carried out current frame’s data calculate optimal...

Autonomous driving has long grappled with the need for precise absolute localization, making full autonomy elusive and raising capital entry barriers startups. This study delves into feasibility of local trajectory planning level-2+ (L2+) semi-autonomous vehicles without dependence on accurate localization. Instead, we emphasize estimation pose change between consecutive frames from motion sensors integration relative locations traffic objects to problem under ego car's coordinate system,...

Oriented towards the stiffness optimization of parallel manipulators, a modeling method based on subspace analysis was proposed. The paper revealed “shielding effect” passive joints, i.e. shielding partial local mechanism Cartesian space, and accordingly brought forward concept Effective Stiffness Tensor (EST), which then obtained by introducing orthogonal projector. allows model analytical form as well high computation efficiency, makes it suitable for applications in manipulators. Proposed...

Abstract In view of the poor tracking performance conventional control method in differential scanning calorimeter during constant speed heating progress, a DMC-PID cascade algorithm for calorimetry is proposed. Firstly, based on predictability and optimality DMC algorithm, controller used main circuit to generalized object composed PID reheating furnace. Secondly, basis characteristics that can improve dynamic controlled object, secondary loop system linearity object. Finally, proposed...

This paper presents a new 6 degree of freedom(6-DOF)secondary mirror alignment mechanism for space optical payload. The moving platform is connected to the base by six kinematic branch chains, each chain composed Prismatic joint P, two Offset RR-hinges and Revolute R. Compared parallel platforms with universal configuration, forward kinematics problem much more complicated due existence dependent variables. In this paper, numerical solution presented solved Newton-Raphson method. simulation...

A moving horizon H/sub /spl infin// disturbance attenuation scheme for active suspensions with time-domain constraints is suggested, where closed-loop dissipation and hence performance are guaranteed. By minimizing the level online, system able to relax requirement so as meet hard in case of unforeseen large disturbances, recover a better generally mild disturbances. Simulation results 2 DOF quarter-car model presented.

This paper studies the problem of tracking control under-actuated surface vessel (USV) with given trajectory under external disturbances. A backstepping sliding mode method based on pre-set performance is proposed to improve transient response performance. Firstly, by introducing function, USV error model transformed into an equivalent conversion model, so that original restricted system converted non-restricted system. Secondly, position stabilized a virtual velocity and second-order...