Papers by Keyword: Working Space

Abstract: In order to help patients with wrist injuries to carry out recovery training, a simple and portable parallel 3-RSR wrist rehabilitation mechanism was introduced in order to achieve the expected therapeutic effect. Firstly, the parallel 3-RSR wrist rehabilitation mechanism is described. Taking the parallel mechanism as the research object, the degree of freedom is calculated and the pose is solved by analytical method, which verifies the rationality of the mechanism motion. Then, based on the boundary search method, the reachable workspace of the parallel wrist rehabilitation mechanism is analyzed, and the relevant workspace map is drawn. Finally, considering the reasonable optimization of the structural size of the workspace, the results show that the optimized reachable attitude workspace is significantly larger than the initial workspace. This study provides a theoretical reference for the ontology design of rehabilitation institutions.

Abstract: This article is based on ADAMS software platform to solve working space of the 4-DOF parallel mechanism. Design a kind of 4-DOF parallel mechanism and establish virtual prototype on ADAMS software platform. Then through enumeration three branched chain parameters combination, even without the premise of kinematics positive solution, we can solve it working space using the forward solving method and get the branched chain parameter with the reference point position corresponding numerical relations. It greatly simplifies the solution of the working space of parallel mechanism, is more advantageous to parameter optimization and trajectory planning of parallel mechanism.

Abstract: The article considers the previously presented manipulating mechanism for positioning of a microphone during acoustical measurements in anechoic chamber. Usually the aims of acoustical measurements in anechoic chamber are: estimation of Sound Power Level of the noise source, measurement of directional characteristics of an electroacoustical transducer, measurement of the sound diffusion characteristic of a given structure and a measurement of Sound Pressure Level on a given measurement grid. The specific of that kind of measurements brings up the need of measurement microphone positioning in many points of the measurement space accordingly to relevant standards. In most cases during the tests it is necessary to position the microphone in certain points on the hemisphere. In such cases utilizing of typical microphone stands impedes the measurement and extends the time needed for the tests. The presented manipulation system for a measurement microphone allows positioning the microphone on the hemisphere around the tested object as required by the standards on the Sound Power Level measurement. Its construction is a simple, rigid form aiming at little effect on the acoustic field inside the chamber whereas the control system and the software are targeted at the maximal flexibility that allows not only standard testing but also scientific research in freely selected scenarios. Since its initial introduction the system has been extended by an additional axis that is used for rotating the microphone, which allows its positioning on the line that is coincident with the centre of rotation of the turntable. Such an extension eliminates the problem of use of the corrections of the directional characteristics of the microphone when measuring the sound signal. The microphone can be positioned directly towards the source of the sound. The article briefly reviews the mechanical construction of the positioning mechanism and focuses on the structure of the control section of the drive system constructed in the manipulator. The method for cooperation of actuators and the control system is presented. Also the description is given for the internal structure of the multi-level control circuits built in the applied drives. Finally the structure of the control application is presented.

Abstract: The palletizing robot mechanism was investigated in this paper. The concepts of the metamorphic mechanism and controllable mechanism were introduced into the design of palletizing robot mechanism, a novel controllable metamorphic palletizing robot mechanism with geometric limit, which can achieve a variety of flexible action, was designed. The working space of output of the controllable metamorphic palletizing robot mechanism was obtained through simulation study, and the kinematics characteristics of the mechanism were analyzed. The work of this paper provides some references for the practical application of such kind of mechanism in the palletizing robot.

Abstract: This paper mainly focuses on applying graphical method to figure out the working space of the new five joint folding arm supported pumper based on ADAMS. Firstly, discrete the included angle α between the third and the forth arm support, pick out several special points, work out the changing curve of the included angle β in the region of [0,180°] between the forth and the fifth arm support, and then get the plane track of the motion of spray gun by superposition of those curves and finally take the effect of turn angles of rotary tables into consideration, figure out the three-dimensional working space track of the spray gun by the superposition of plane track curves in the region of [0,360°].

Abstract: A new type of machine for complex structure decoration materials based on hybrid cubic manipulator with six degree of freedom(DOF) suggested in view of traditional serial manipulator and parallel manipulator, three dimensional translation and rotation of output shaft obtained through lineal driving. Define the description of spacial moving capability of common couples and translation base and rotation base of mechanism, based on the fact of mechanism consists of components, a new description method by topological graph theory of components relationship suggested, new description of serial mechanism and parallel mechanism and hybrid mechanism obtained with this method, description elements include component pane and constrained component pane and component relationship line and constrained component relationship line and spacial relative moving capability between adjacent components. DOF(degree of freedom) of hybrid mechanism analysised with example based on the definition of dimensionity of branch spacial moving capability and mechanism spacial moving capability, necessary and sufficient condition of nonsingularity of mechanism presented. Method of analytic geometry used to find the regular cuboid of the reachable working space shape of mechanism, the volume of the reachable working space rest with the limit of translation of couplers, its influential factors obtained, limit length of guideway etc. are the primary influential factors.

Abstract: the robot working space is the volume which a reference point on its wrist to be reached. It is an important evaluation index of the robot geometry characters. Firstly, the size of the movable cotton robot palletizer structure is calculated by analyzing its movement, then, its working space is calculated base on graphing method. This method is working as these: a referent point P on the wrist is selected, the space of it reaching will be the volume which is the movable cotton robot palletizer working space, by fixing a limiting position at a robot wrist, the reference point P on the total working space XOY is analyzed by drawing, the geometrical analysis and calculation method are used to acquire the motion curve equation, within XOY plane, the movement of the wrist and two slides is decoupling to calculate the limiting position of the robot wrist movement, at the end, the final movement space of the robot is determined.

Abstract: Taking a 5-axis-5-swivel parallel machine tool with swivel joints as an example, a geometric method is put forward in the paper to solve this kind of parallel machine working space. In this method, the border of the working space is found when several curves cap. This geometric mathematical model reveals the relationship betiten the structure parameters and the working space. The maximum proportion of the volume of working space is used as a target of evaluation ,and how scale parameters affect this target is also discussed. With this method, the condition of constraints could be got from the machine principles and the working space is also directly calculated. Hence, no more complex derivation process is needed.

Abstract: Different methods adopted to study the working space of robot other than the traditional software methods, used block diagram in control theory to describe the transfer function of the kinematical chain of robot based on decomposition, digital and logical circuit of electronic technology with the foregoing result, data acquisition of dexterous working space and singular working space can be easily found then.

Abstract: Based on the partial derivative of working space function, define the integral field of serial mechanism and parallel mechanism and serial-parallel mechanism respectively, judge conditions of singularityity including dead point and limit point with one and two and three input parameters obtained. Define the coupling degree of each input variable of mechanism use the second-order partial derivative of working space function, decoupling property between input variable identified by judging the coupling degree equal zero or not. Based on the realtionship between working space function and input variables, as well as relationship between input variables and time, three new index to weigh the kinematical properties of mechanism defined, positioning accuracy influence factor and dynamic response influence factor and sensitivity influencefactor included, its physical meaning and computation process presented as well, new direction provided for the research of kinematical properties of mechanism.