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Using motion capture only, we challenge in this paper the estimation of the contact forces-backed with ground-truth sensing, in human whole-body interaction with the environment. Our method is novel and makes it possible to get rid of cumbersome force sensors in monitoring multi-contact motion and its interaction force data. This problem is very difficult. Indeed, while a given force distribution...
The kinematic performance optimization of a 2-PRR parallel robot based on new variance indices is given in this paper. First, the inverse kinematic equation of the 2-PRR parallel robot is derived. Then the velocity performance evaluable indices LCI and GCI, the stiffness performance evaluable indices LSI and GSI are analyzed. To consider the distribution of the LCI and LSI in the global indices, two...
The design of lever amplification mechanism plays the crucial rule in the performance of double-feet piezoelectric linear motor which is based on the lever amplification principle. The kinematic principle of double-feet piezoelectric linear motor based on the lever amplification mechanism was analyzed and the dynamic model of the lever amplification mechanism based on the flexure hinge was established...
The bevel-tip flexible needle is an improvement of the clinical puncture needle and has the potential to reduce surgery traumas and improve puncture accuracy. Due to the nonholonomic kinematics model, it is difficult to drive flexible needles to track a pre-plan path. In this paper, we propose an effective path tracking control method based on Model Predictive Control (MPC). The kinematics model of...
This paper studies the optimal distribution of feet forces and control of multilegged robots with uncertainties in both kinematics and dynamics. First, a constrained dynamics for multilegged robots and the constrained environment model are established by considering both kinematic and dynamic uncertainties. Under an external wrench for multilegged robots, the foot forces and moments of the supporting...
This work proposes an approach to manipulate unknown objects based on tactile information. The manipulation can have three goals: the optimization of the hand configuration, the optimization of the grasp quality and the optimization of the object configuration. Three different motion strategies are introduced in order to move the fingers trying to deal with each of the three goals. The strategies...
Powered exoskeletons can provide motion enhancement for both healthy and physically challenged people. Compared with lower limb exoskeletons, upper limb exoskeletons are required to have multiple degrees-of-freedom and can still produce sufficient augmentation force. Designs using serial mechanisms usually result in complicated and bulky exoskeletons that prevent themselves from being wearable. This...
This paper presents a method to transfer functional grasps among objects of the same category through contact warping and local replanning. The method transfers implicit knowledge that enables an action on a class of objects for which no explicit grasp or task information has been given in advance. Contact points on the source object are warped based on global and local shape similarities to the target...
Soft actuators can be useful in human-occupied environments because of their adaptable compliance and light weight. We previously introduced a variation of fluidic soft actuators we call the reverse pneumatic artificial muscle (rPAM), and developed an analytical model to predict its performance both individually and while driving a 1 degree of freedom revolute joint antagonistically. Here, we expand...
In this paper, we propose an optimization scheme for deriving task-specific force closure grasps for underactuated robot hands. Motivated by recent neuroscientific studies on the human grasping behavior, a novel grasp strategy is built upon past analysis regarding the task-specificity of human grasps, that also complies with the recent soft synergy model of underactuated hands. Our scheme determines...
For the real-time adjustment of the Satellite Integrated Assembly, Stewart platform-based mechanism is adopted. This paper presents the optimization design of the parallel adjustment platform for satellite integrated assembly and the analysis of the configuration is optimized. The actual working conditions and real limit of system size is considered when optimizing the configuration. Placing the moving...
This paper examines the extent to which nonlinear dimension reduction techniques from machine learning can be exploited to determine dynamically optimal motions for high degree of freedom systems. Using the Gaussian Process Latent Variable Model (GPLVM) to learn the low-dimensional embedding, and a density function that provides a nonlinear mapping from the low-dimensional latent space to the full-dimensional...
This paper discusses multi-criteria optimization of the 4 links of an 8 DOF haptic master device for a minimally invasive surgery. In minimally invasive surgery, because of limited information from surgical scene, sensation of feedback force and manipulability of device are important factors during surgery. Therefore, optimization of the device is required for efficiency of surgical procedures. To...
In Programming by Demonstration (PbD), one of the key problems for autonomous learning is to automatically extract the relevant features of a manipulation task, which has a significant impact on the generalization capabilities. In this paper, task features are encoded as constraints of a learned planning model. In order to extract the relevant constraints, the human teacher demonstrates a set of tests,...
A kinematic optimization procedure for redundantly actuated parallel manipulator is developed to ensure the isotropic antagonistic stiffness in a workspace. The kinematic parameters of the mechanism are optimized to maximize and equal out antagonistic stiffness of the redundantly actuated manipulator when size and shape of the usable workspace are given but position in the entire workspace is not...
When dealing with the design of robotic fingers driven by tendons, one can be inspired by the human index finger tendon distribution. The structure of the designed robot finger has to minimize the number of tendons required without sacrificing either the actuated degree of freedom or the maximal output force produced at the fingertip. In this paper, a biomechanical study of the index finger under...
To prevent the human injury or breakage of the robot caused by interaction or collision with the robot and its environment, it is an important issue to introduce robot softness. However, because not only softness but also stiffness is required for precise task execution, the simultaneous realization of softness and stiffness using time varying stiffness is required in the real environment. We focus...
In this paper, a new methodology for the optimal design of parallel kinematic machine tools is proposed. This approach is based on the concept of the maximal inscribed parallelepiped and uses technology-oriented constraints that are motivated by particular applications. This methodology is applied on two translational parallel robots with three degrees-of-freedom (DOF): the Y-STAR and the UraneSX...
On the basis of analysis of mechanism about crankshaft fillet rolling, the sliding motion in rolling process is classified into elastic sliding caused by elastic deformation of material and geometry sliding caused by geometrical shape and relative position of sliding pair. Aiming at the issue of sliding in crankshaft rolling process, the kinematical model of fillet rolling machining is established...
In order to meet the requirement of manufacturing large-scale ball-crown like parts, a new type Slider-crank Mechanism Based 2-dof Heavy-load Positioner is introduced in this paper. The mathematical model of the positioner is established. The kinematics problems are solved. The statics problem is solved and the analytic expression of the driving force is obtained. An optimal dimensional synthesis...
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