Top PDF Development of a 6 DOF Parallel Serial Hybrid Manipulator

Development of a 6 DOF Parallel Serial Hybrid Manipulator

Development of a 6 DOF Parallel Serial Hybrid Manipulator

A design approach to analysis of industrial manipulator kinematic chain is described by Cubero [6]. The method generates plane mechanical structures with different DOF. The generalized solution for kinematics and dynamics of serial manipulators is presented [7] using 4*4 homogenous transformation matrix and Jacobian matrix. Singh et al [8] presented a computational algorithm to solve robot kinematics using D-H Parameters, differential transformation matrix theory. The inverse kinematics models of a serial manipulator maps the Cartesian workspace to the joint space. The solution to inverse kinematics problems are difficult to solve since the relation between the two spaces is nonlinear and can have multiple solutions. Pashkevich [9] developed algorithms for inverse transformation of coordinates (analytical) kinematics of robotic manipulators. The solutions obtained possess good convergence including singularity positions. The Inverse kinematics and dynamic algorithms were also presented in [10]. In this case, the robot is controlled by the joint actuation (torques and forces) to produce the end effector trajectory. The complexity of the inverse kinematics increases with increase in number of links.
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Neural Network Solutions for Forward Kinematics Problem of Hybrid Serial-Parallel Manipulator

Neural Network Solutions for Forward Kinematics Problem of Hybrid Serial-Parallel Manipulator

Artificial neural network (ANN) is a parallel-distributed information processing system. This system is composed of operators interconnected via one-way signal flow channels. ANN stores the samples with a distributed coding, thus forming a trainable nonlinear system. It includes hidden layer(s) between the inputs and outputs. The main idea of the ANN approach resembles the human brain functioning. Therefore, ANN has a quicker response and higher performance than a sequential digital computer. Given the inputs and desired outputs, it is also self-adaptive to the environment so as to respond different inputs rationally. Various neural networks have been used to solve the kinematics problem [15]. They include the multi layer perceptron network (MLPN), cerebellar model articulation controller (CMAC) and radial basis function network (RBFN). Here we use MLPN and RBFN for solution forward kinematics of 2(6-UPS) and presented a comparison between MLPN & RBFN.
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Chatter-free and equivalent estimator fuzzy model-based sliding mode controller for serial links 6 dof robot manipulator

Chatter-free and equivalent estimator fuzzy model-based sliding mode controller for serial links 6 dof robot manipulator

The first problem in the design of a robust SMC is to reduce or eliminate the chatter phenomenon, because this problem causes heating and oscillation in the mechanical parts of the system. Many researchers have found ways to reduce the chatter but they have also lost system stability based on their methods. In this research the reduction or elimination of chatter in order to maintain robustness is one of the main objectives. The switching function causes the chatter but it is one of the significant parts of the design of a robust and high speed SMC. In the SMC, the slope of the sliding surface (λ) is the second factor to control the chatter. As a result one of the main tasks in the first objective is to reduce or eliminate the chatter in the SMC based on the design of parallel linear control methodology and a discontinuous part. The SMC and linear control methodologies are robust based on the Lyapunov theory. The stability of the Lyapunov theory has been proven in proposing a chatter-free SMC based on switching theory.
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Dimensional Synthesis of Kinematic Dexterity and Workspace for 3-DOF Parallel Manipulator

Dimensional Synthesis of Kinematic Dexterity and Workspace for 3-DOF Parallel Manipulator

Compared with traditional serial robotics, the parallel manipulators have some significant advantages including higher accuracy, higher stiffness, higher loading capacity, less error accumulation, and more convenient for inverse kinematic control. Up to now, parallel manipulators as an emerging area have shown great application potential for the development of machine tools in virtue of their excellent mechanical properties mentioned above [1]-[4]. However, the main disadvantage of the parallel manipulators is the limited workspace, because these legs will collide to each other and each leg has several different joints which limit the motion of parallel manipulators as well. Therefore, it is quite necessary to perform the dimensional syntheses optimum analysis in the early design stage for the next-generation robotic systems for industrial applications with higher accuracy and higher speed, more robustness and adaptability, and so on.
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Design and development of a 6-DOF system for virtual bicycle simulator

Design and development of a 6-DOF system for virtual bicycle simulator

There are many variations of the competition that takes place in Olympic track cycling. Hence, a bicycle simulator will provide a number of benefits to coaches and athletes in practical training. It is extremely low cost compared to a real Velodrome track, which requires a long construction time due to the unique geometry and size. In this project, a 6-degree-of-freedom (6- DOF) motion platform is designed and developed to simulate the Velodrome track cycling. A parallel manipulator was chosen to control the moving platform due to its higher accuracy and greater weight to strength ratio compared to a serial manipulator. The 6-DOF platform is controlled by linear actuators and micro-controller. An optical encoder was installed for closed- loop position feedback control. An inverse kinematics model was developed to obtain the movement of the platform and validated with its CAD model. Furthermore, a design feasibility program was developed to determine the optimum design dimensions for the motion platform. All the positions (3-axes) and orientations (3-rotational axes) data are tracked for analysis purpose. A lab-scale prototype was successfully built for analysis and validation purposes. A standard Velodrome track dimensions was chosen for simulation. A gyro accelerometer was installed at the platform to acquire the actual motion of the platform. The data is used to validate the control algorithms and accuracy of the motion platform. The experiment was conducted and the results analysed for further development.
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Kinematic and Dynamic Analysis of 6-UPS Parallel Robot II. KINEMATIC ANALYSIS OF 6-DOF PARALLEL ROBOT

Kinematic and Dynamic Analysis of 6-UPS Parallel Robot II. KINEMATIC ANALYSIS OF 6-DOF PARALLEL ROBOT

The particularity of parallel robot structure makes it have the advantages which the serial robot doesn’t have, This has caused wide attention of the international academic community. Most 6-DOF parallel robot is based on the structure of Stewart platform, 6-DOF parallel robot has the following advantages: it can meet the needs of most industrial operations, mechanism of the complexity and the cost is low, kinematics and dynamics model is relatively simple, and the control is easy. Therefore, the 6-DOF parallel robot has broad application prospect. Such as 1983, HUNT [1] proposed the 6-DOF mechanism, it gets a wide range of applications because of its two rotations and a mobile. LEE [2-3] analyzed kinematic and dynamic of 6-DOF mechanism, and they used the mechanism as the main arm of 6-DOF robot manipulator. The optimal design of kinematic for planar 6-DOF parallel manipulator was analyzed by GOSSELIN [4] .The differential kinematics of 6-DOF parallel manipulator is studied by FANG [5-6] .The instantaneous motion of 6-DOF is analyzed by using the screw theory. The position of the 6-DOF mechanism based on the symmetric structure of the 6-DOF parallel robot was studied by FANG [7-8] . Based on the relationship of system differential movement, Li Jianfeng [8] analyzed the kinematics and dynamics of the parallel mechanism of 6-DOF. The kinematics of the 6-DOF parallel robot was analyzed by CARRETERO [9] , and the parameters of the system were optimized by using the nonlinear optimization method. WANG [10] studied the static balance problem of 6-DOF parallel robot by adding weights and springs. However, the types and the number of the parallel mechanism are so much, the kinematics and dynamics of the parallel mechanism is still insufficient.
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Kinematic and Dynamic Analyses of Tripteron, an Over-Constrained 3-DOF Translational Parallel Manipulator, through Newton-Euler Approach

Kinematic and Dynamic Analyses of Tripteron, an Over-Constrained 3-DOF Translational Parallel Manipulator, through Newton-Euler Approach

Over the past decades, many novel designs have been proposed to overcome workspace limitations of the PMs, including: axis-symmetric PMs [3-5] which employ 2-7 actuated arms rotating around a common axis of rotation and robots with actuated carts on parallel guide-ways, e.g. Tripteron, Quadrepteron and Pentaptereon from the Université Laval Canada [6, 7]. Despite all disadvantages that limit the use of PMs, such as smaller workspace, they offer some advantages over serial manipulators like high rigidity, high speed, acceleration and accuracy [2]. Nowadays, PMs due to their high positional accuracy and high speed are used in several industries, such as CNS machining tools which are referred to as Parallel Kinematic Machine [8]. In theory, a PM allows for a better dynamic performance than a serial one [1]. The 3-DOF translational PM under study, called Tripteron, was first built at the Laval University [9]. It belongs to a class of PMs known as Multipteron [10] which is arisen from the type synthesis performed for PM exhibiting three translational motion patterns. The kinematic analysis of the Multipteron family was discussed in [10] and the inverse and forward kinematic of Tripteron and its singularity analysis were investigated in [11]. In [12], experimental results of the controlling of a 3-DOF DPM via an HRI interface was given. The objective of the inverse dynamics’ model of a mechanism Corresponding author; Email: m.t.masouleh@ut.ac.ir
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Workspace Performance Investigation of a Multi-DOF Parallel Robot Manipulator

Workspace Performance Investigation of a Multi-DOF Parallel Robot Manipulator

As is known to all, integrated manufacturing technology highly relies on the development of higher performance robotic system. Compared with serial robots, the parallel manipulator has different potential advantages, including high stiffness, high accuracy and high loading capacities. However, the workspace of the parallel manipulator is relatively low. So it is necessary to research the workspace in the engineering application. Evaluation and optimization of the kinematics performance is the basic parallel robot structure design, driver selection and control mechanism. With the increasing application of parallel robot manipulator such as machine tools, simulators, cutting and welding machines as well as CNC machines has aroused general attention [1], [2]. At present, the optimization design of parallel manipulator are mainly concentrated on the workspace, dexterity, accuracy, stiffness and bearing capacity etc., the dexterous workspace are the most important kinematics performance index widely used to evaluate the kinematics accuracy. Recently, many scholars have studied on the five degrees of freedom parallel manipulators, such as Wang [3] analyzed the kinematics of a
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Design of a multi DOF cable driven mechanism of a miniature serial manipulator for robot assisted minimally invasive surgery

Design of a multi DOF cable driven mechanism of a miniature serial manipulator for robot assisted minimally invasive surgery

Tendon driven mechanisms impose coupling of the joints’ motion and complicate their actuation and control, while there is also the risk of tendons breaking during an operation. Other methods include the use of shape memory alloy [3], al- though grasping forces seem insufficient for use in abdominal surgery. Hong et al. use a parallel rigid link mechanism with the drive unit integrated into the instrument’s shaft [5]. MICA also has its motors integrated into the instrument in order to aim for versatility and low cost as the tool is detachable [6].

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Analysis and Optimization of a Spatial Parallel Mechanism for a New 5-DOF Hybrid Serial-Parallel Manipulator

Analysis and Optimization of a Spatial Parallel Mechanism for a New 5-DOF Hybrid Serial-Parallel Manipulator

In the processing industry, most of the complex space surfaces (such as the surfaces of engine blade, propeller blade, and nuclear evaporator head) need five-axis simul- taneous machining center. Consequently, using the five or six DOFs PMs is an appropriate choice, but the multi- DOF PMs are composed of multi-hinge and multi-chain. Under the influence of the complicated self-structure, the orientation capability of multi-DOF PMs is limited. And the high kinematic coupling, complicated dynamics model, hard control also should be noted. Taking these disadvantages into account, the structure of machines should be improved. Therefore, the hybrid serial-parallel manipulators (HSPMs) based on the 2R1T PMs may be a trend, which present a compromise between the high stiffness of PMs and the good flexibility, large workspace of serial mechanisms [10, 11]. For example, the 5-axis FSW proposed by Li [12], is installed by concatenating a 2-DOF PP serial mechanism on the 2R1T PM 2SPR/RPS. The Tricept [13], Trivariant 5-DOF HSPM [14] and Exe- chon five-axis machining center [15] are constructed by concatenating the 2-DOF sway heads on the MPs of the 2R1T PMs: 3UPS/UP, 2UPS/UP, and 2UPR/SPR, respec- tively (U stands for universal joints).
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Design and Kinematic Analysis of a 4-DOF Serial-Parallel Manipulator for a Driving Simulator

Design and Kinematic Analysis of a 4-DOF Serial-Parallel Manipulator for a Driving Simulator

Early simulators were used extensively in the aviation industry for aircrew training [1]. The development and advent of industrial Parallel Mechanisms (PMs) gained popularity in other fields such as ground vehicle driving simulators and CNC machines. In [2], a comprehensive report is presented on the development history of simulators from 1948 to 2007. In 1994 and 2003, Ford and BMW, two major car companies, developed two six- degree-of-freedom (DOF) driving simulators. These simulators generate their motion by their hydraulically- actuated hexapod mechanisms [3, 4]. In the academic side, the National Advanced Driving Simulator (NADS) at the university of Iowa developed a few driving simulators becoming the state of the art for other car companies due to their great success [5]. For example, the Toyota Driving Simulator [6] is inspired by NADS products. In 2004, TUTOR, a truck driving simulator was developed at INTA (Spain) [7]. Selecting the best possible set of DOFs for a driving simulator is of paramount importance. In this paper, from the study
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Integrator Backstepping Control of a 5 DoF Robot Manipulator with Cascaded Dynamics

Integrator Backstepping Control of a 5 DoF Robot Manipulator with Cascaded Dynamics

In this paper, using the integrator backstepping method develops the problem of nonlinear position control of a 5 DoF robot manipulator. It consists of elaborating a control method [13] that guarantees the asymptotic stability and the tracking of desired position and velocity trajectories. A major advantage of this method is its flexibility to build the control law by avoiding the cancellation of useful non-linearities [8]. Simulation results presented in this paper show that the system has global stability.

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Simulation 3 DOF RRR Robotic Manipulator under PID Controller

Simulation 3 DOF RRR Robotic Manipulator under PID Controller

The Lagrangian dynamic formulation (White et al., 1989; Yu et al., 2015) provides a means of deriving the equations of motion from a scalar function called the Lagrangian which is defined as the difference between the kinetic and potential energy of a mechanical system. The Lagrangian of a manipulator is:

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EVO: A geometric approach to event-based 6-DOF parallel tracking and mapping in real-time

EVO: A geometric approach to event-based 6-DOF parallel tracking and mapping in real-time

Abstract: We present EVO, an Event-based Visual Odometry algorithm. Our algorithm successfully leverages the outstanding properties of event cameras to track fast camera motions while recovering a semi-dense 3D map of the environment. The implementation runs in real-time on a standard CPU and outputs up to several hundred pose estimates per second. Due to the nature of event cameras, our algorithm is unaffected by motion blur and operates very well in challenging, high dynamic range conditions with strong illumination changes. To achieve this, we combine a novel, event-based tracking approach based on image-to-model alignment with a recent event-based 3D reconstruction algorithm in a parallel fashion. Additionally, we show that the output of our pipeline can be used to reconstruct intensity images from the binary event stream, though our algorithm does not require such intensity information. We believe that this work makes significant progress in SLAM by unlocking the potential of event cameras. This allows us to tackle challenging scenarios that are currently inaccessible to standard cameras.
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Kinematics of a Spatial RCCC Parallel Manipulator

Kinematics of a Spatial RCCC Parallel Manipulator

To define the geometry of the parallel manipulator the Cartesian coordinate systems UWV and XYZ are used which are fixed with elements of kinematic pairs. The axis W and Z of the coordinate systems UVW and XYZ are directed along the axis of rotation or translation of the kinematic pairs elements, and the axis U and X are directed along the shortest distance the axis W and Z. The axis V and Y supplement the coordinate systems UVW and XYZ. The transformation matrix between the coordinate systems UVW and XYZ is made up [4]. The constant and variable parameters of the parallel manipulator structural scheme are the elements of this matrix. The transformation matrix T jk between the coordinate systems U j V j W j and X k Y k Z k that are fixed on the ends of the binary link has a view
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Kinematic calibration of a 6 DOF hybrid robot by considering multicollinearity in the identification Jacobian

Kinematic calibration of a 6 DOF hybrid robot by considering multicollinearity in the identification Jacobian

This paper has proposed and explored a systematic approach for the kinematic calibration of a 6-DOF hybrid robot developed for polishing aspheric lenses. This approach improves the calibration efficiency and accuracy by implementing two successive steps: (1) estimation of the encoder offsets by ordinary least squares (OLS) in an iterative manner until an overall linearized regression model becomes valid; and (2) estimation of the whole set of identifiable error parameters using a Liu estimator on the basis of a column full ranked identification Jacobian reconstructed by correlation analysis. For the prototype machine under investigation, simulation results confirm improved robustness against measurement disturbances by showing that the overall standard deviation of the whole set of identifiable error parameters estimated by LE is 63.9% smaller than that estimated by OLS. Experimental results demonstrate the effectiveness of the approach: following fine calibration the maximum value of the volumetric position and orientation errors of the polishing head can be reduced below 0.06 mm and 0.06 deg by LE in comparison with 0.10 mm and 0.10 deg by OLS throughout a task workspace of 500 mm 500 mm 120 mm   .
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Human Machine Interface Design for a 3 DoF Robot Manipulator

Human Machine Interface Design for a 3 DoF Robot Manipulator

The world industry has developed rapidly since the beginning of the first industrial revolution. This evolution still continues and now 4th industrial revolution is started. In the last revolution, automation lines must be designed to manufacture flexible products which are specified by costumer needs. In planning of automated production lines, engineers need various designs of robot manipulators for picking and placing, painting, welding, assembling and similar tasks. Therefore, the robot manipulators are the most important part in flexible automated lines. According to task of the robot manipulator, motion of the end effector can be spatial or planar.
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Pose Accuracy Calibration of a Serial Five DOF Robot

Pose Accuracy Calibration of a Serial Five DOF Robot

A laser tracker LTD 840 showned in Fig4 was used here to calibrate the pose errors of the robot. The laser tracker is composed of tracker head, retroreflector, controller, measurement software. There are a set of laser interferometer, two angluar tranceducer, two degree of freedom gimbal, motors and detector in the tracker head. Its accuracy is 0.075mm in 2m domain and not more than 0.015mm in 10m domain, which can meet the measurement accuracy demand[4,5]. The work principle schematic of the laser tracker is showninFig. The procedure of the calibration experiment is as follows. First, a target mirror was mounted to the tool flange of the robot. The measurement laser beam was directed to the target mirror located on the tool flange and the returning beam from the target mirror went parallel to the tracking mirror. Then the robot moved according to the preestablished program. As the movable target mirror changed its position, the tracking mirror rotated axes of the gimbal by motors to track the target mirror position. A Dopple frequency shift of the beam is occurred. The frequency shift translated through interferometry to a relative displacement reading. The pitch and yaw angle of the gimbal can be measured with angle encoder. At last, the measurement software compute the location of each point in the refence coordinate system[6]. The results of the calibration DH parameter are shown in Table 3.
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Fuzzy Logic Washout Algorithm Based on Serial Manipulator

Fuzzy Logic Washout Algorithm Based on Serial Manipulator

The motion simulator, which appeared in the 70s of last century, is widely used in flight simulation, vehicle road simulation, aviation and navigation simulation, robot, parallel machine tool, space docking technology and entertainment facilities by simulating the movement of aircraft and ships in the motion simulator[1].

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Fuzzy-PID Controller Design of 4 DOF Industrial Arm Robot Manipulator

Fuzzy-PID Controller Design of 4 DOF Industrial Arm Robot Manipulator

This paper presents Fuzzy-PID controller of a 4 DOF arm robot manipulator applied in industry. The design started with FLC design to detect the manipulated object. FLC decides robot motion based on color green detection. The mechanical and electronics designs are also presented. Robot motion is simulated by RSTX toolbox in SciLab to checked whether the robot moves as expected. The simulation of robot motion is possible by inputting the DH parameters derived from mechanical design. PID controller is combined with FLC to ensure the motion smoothness and stability
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