Catálogo de publicaciones - libros

A method for the simulation of human movements driven by real data and correlated with modification of constraints in the external environmental is presented. It was applied to the simulation of the car ingress changing the configuration of the doorway to check early on in the design the man-machine-interface requirements for choosing the best ergonomic solution among different alternative solutions without the physical construction of prototypes. The method for the simulation of the movement is based on the modulation of a real measured performance recorded through an opto-electronic system for motion analysis. The algorithm implements a multifactorial target function to solve the redundancy problem. The reliability of the method was tested through the comparison of simulated and real data showing promising developments in ergonomics.

This paper introduces a data-based approach to simulate with digital human models hand postures for grasping car control objects, which takes into account hand anthropometry, grasp type and object size. This paper presents more the experimental approach part than the simulation part itself. The simulation part is essentially done by the RPx software. This paper presents mainly a protocol in order to obtain data for the simulation.

To build a criterion of discomfort evaluation, based on the kinematics and the dynamics of the performed movement, is an expectation of the car manufacturers. There is no reference concerning the evaluation of the articulation efforts during the automobile vehicle accessibility movement. On this point, we propose to give a first reference. Our method and our computation were verified by a well known movement, the walking. The automobile vehicle accessibility movement of a young and healthy subject is studied. The articulation efforts presented are coherent with the produced movement’s analysis.

The evaluation methods of hand fatigue are built and the aim is to provide reference for the numerical human fatigue appraisal. Method 12 females and 14 males in two groups participated in the experiments of changeless force fatigue, which included the grip and pinch and screw, and took part in the nondimensional force fatigue. Result Hand fatigue could be full evaluated basing on grip and pinch and screw. Using stable force could test the fatigue of manual work simply, but it would be largely affected by the characteristic of sex. The nondimensional evaluation can avoid the impact results from the different forces of testees. Conclusion Hand fatigue could be full evaluated basing on grip and pinch and screw. The nondimensional evaluation is a feasible method to research numerical human manual fatigue.

Moveable human body model can be built based on human motion data, which is recorded by the VICON optical motion capture system and imported to the MOTION BUILDER software. In this experiment, two simulation projects were designed successfully, and satisfying results were obtained. The first test was an arm swinging test which simulates the pilot’s action of manipulating dashboard. The other test involved arm swinging, walking and turning in standing mode, focused on testing the stability of the system in multi-degree-of-freedom complex motion situation

The purpose of this study is to construct a new pointing movement model considering the effect of target position. A pointing movement experiment was designed and carried out, and the pointing movement characteristics when human upper limb touched the targets on front board are studied. The result shows that the starting point position and target position greatly affect the movement time. A new pointing movement model is built, in which the effect of target position is introduced. The new model obtains higher contribution value and could describe the data better than the conventional models.

Particle swarm optimization (PSO) is a stochastic, population-based optimization technique that is inspired by the emigrant behavior of a flock of birds searching for food. In this paper, a nonlinear function of decreasing inertia weight that adapts to current performance of PSO search is presented. Meanwhile, a dynamic mechanism to adjust decrease rates is also suggested. Through the experimental study, the new PSO algorithm with adaptive dynamic weight scheme is compared to the exiting models in terms of various benchmark functions. The computational experience shows some great promise.

On the way to a generalized discomfort model for movements steps are presented that calculate the determining parameters for the model. Discomfort is mainly dependant on posture and relative torque. A multi body system arm model is used to calculate the driving torques of a lifting task using inverse dynamics. A motion analysis of the movement was carried out and the corresponding angles were used to drive the arm model. In order to calculate relative torque a torque velocity relationship according to Hill was implemented in the arm model.

A motion compensated de-interlacing algorithm is proposed to recover the defects of interlaced video frame for capturing motion object. In this algorithm, two anti-noise background fields are formed by analyzing the temporal correlation of pixels between adjacent same parity fields. To each field, the subtraction with the corresponding background is used to detect motion object. To avoid the inaccurate detection caused by the difference between the spatial scanning positions of odd and even field, the motion objects are detected with same parity field and background field. Then motion estimation technology is used to measures the inter-field motion, find out the motion vector between the odd field and even field. Based on the motion vector, an interpolation filter is designed to shift the pixels of the motion object in the two temporally displaced fields to a common point in time. This de-interlacing algorithm maximizes the vertical resolution of the motion objects. Experimental results show that the proposed algorithm could achieve higher image quality on motion object, and the computational complexity is acceptable for consumer computer applications.

With the rapid advancement in laser technology, computer vision, and embedded computing, the application of laser scanning to the digitization of three dimensional physical realities has become increasingly widespread. In this paper, we focus on research results embodied in a 3D human body color digitization system developed at Tianjin University, and in collaboration with the Hong Kong University of Science and Technology. In digital human modeling, the first step involves the acquisition of the 3D human body data. We have over the years developed laser scanning technological know-how from first principles to support our research activities on building the first 3D digital human database for ethnic Chinese. The disadvantage of the conventional laser scanning is that surface color information is not contained in the point cloud data. By adding color imaging sensors to the developed multi-axis laser scanner, both the 3D human body coordinate data and the body surface color mapping are acquired. Our latest development is focused on skeleton extraction which is the key step towards human body animation, and applications to dynamic anthropometry. For dynamic anthropometric measurements, we first use an animation algorithm to adjust the 3D digital human to the required standard posture for measurement, and then fix the feature points and feature planes based on human body geometric characteristics. Utilizing the feature points, feature planes, and the extracted human body skeleton, we have measured 40 key sizes for the stand posture, and the squat posture. These experimental results will be given, and the factors that affect the measurement precision are analyzed through qualitative and quantitative analyses.