Optimization of 3-DOF parallel motion devices for low-cost vehicle simulators
01 Jan 2017-Journal of Advanced Mechanical Design Systems and Manufacturing (The Japan Society of Mechanical Engineers)-Vol. 11, Iss: 2
TL;DR: This paper deals with the analysis of the Inverse Kinematics and the reachable workspace of a three-degrees-of-freedom (3-DOF) parallel manipulator, proposing different transformations and optimizations in order to simplify its use with Motion Cueing Algorithms (MCA) for self-motion generation in VR simulators.
Abstract: Motion generation systems are becoming increasingly important in certain Virtual Reality (VR) applications, such as vehicle simulators. This paper deals with the analysis of the Inverse Kinematics (IK) and the reachable workspace of a three-degrees-of-freedom (3-DOF) parallel manipulator, proposing different transformations and optimizations in order to simplify its use with Motion Cueing Algorithms (MCA) for self-motion generation in VR simulators. The proposed analysis and improvements are performed on a 3-DOF heave-pitch-roll manipulator with rotational motors, commonly used for low-cost motion-based commercial simulators. The analysis has been empirically validated against a real 3-DOF parallel manipulator in our labs using an optical tracking system. The described approach can be applied to any kind of 3-DOF parallel manipulator, or even to 6-DOF parallel manipulators. Moreover, the analysis includes objective measures (safe zones) on the workspace volume that can provide a simple but efficient way of comparing the kinematic capabilities of different kinds of motion platforms for this particular application.
Citations
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TL;DR: Comparison results among GA, sequence quadratic programming (SQP) method and interior point method indicate that the proposed method can provide optimized structural parameters of SINS's Stewart platform bumper for restoration accuracy.
12 citations
01 Jan 2018
TL;DR: The following elements have been considered for Vehicle Simulator, Virtual Reality INTRoDUCTIoN and ReLATeD woRK Vehicle:.
Abstract: Vehicle simulators are crucial tools used in a variety of areas, such as aviation, driving, or maritime transportation. International standards require the use of motion-based vehicle simulators in training scenarios. However, the huge variety of applications and requirements makes it difficult for end users to find a motion-based commercial solution that fulfils their needs. On the other hand, commercial solutions are usually expensive as they involve specific hardware and software. Although some adhoc solutions have been reported, a generalized design strategy is needed. In this article, the authors emphasize the need for finding a development methodology for these important tools and they propose an overall strategy for the design of vehicle simulators, focusing on the relevant decisions according to the authors’ learned experience. The following aspects are considered: use, motion hardware, cockpit, users, display types, cost and physical space. Finally, the authors show three case studies where these decisions have been already taken: a rescue speedboat simulator, a tractor simulator and a driving simulator. KeywoRDS Design, Development, Methodology, Motion Cues, Multimodal Interaction, Simulation, Vehicle Simulator, Virtual Reality INTRoDUCTIoN AND ReLATeD woRK Vehicle simulation represents one of the most important mechanisms to train pilots, test new vehicular technologies, study human factors, teach different protocols, practice driving skills or raise awareness about different topics. A large variety of vehicle simulators have been proposed with different applications and vehicle types, such as planes (Advani, Hosman, & Haeck, 2002; Mauro, Gastaldi, Pastorelli, & Sorli, 2016; Reid & Nahon, 1988; Yavrucuk, Kubali, & Tarimci, 2011), helicopters (Schroeder, 1999; Wei, Amaya-Bower, Gates, Rose, & Vasko, 2016; Wiskemann et al., 2014), cars (Chapron & Colinot, 2007; Jansson et al., 2014; Nehaoua et al., 2008), motorcycles (Avizzano, Barbagli, & Bergamasco, 2000; Cossalter, Lot, Massaro, & Sartori, 2011; Nehaoua, Hima, Arioui, Seguy, & Espié, 2007), trucks (Thöndel, 2012), tractors (Lleras et al., 2016), ships (Filipczuk & Nikiel, 2008) or even bicycles (Herpers et al., 2008; Schulzyk, Hartmann, Bongartz, Bildhauer, & Herpers, 2009). Road safety, pilot training and vehicular design are some of the main areas where vehicle simulators can provide significant advantages over experiments with real vehicles, since they can be used to both save money and human lives, among many other advantages (Casas, Fernández, & Riera, International Journal of Virtual and Augmented Reality Volume 2 • Issue 1 • January-June 2018 6
5 citations
TL;DR: In this paper, the authors performed massive experiments with simulated motion platforms of different types, sizes and powers, and found that MCA tuning is of the utmost importance in motion cueing.
Abstract: Motion platforms and motion cueing algorithms (MCA) have been included in virtual reality applications for several decades. They are necessary to provide suitable inertial cues in vehicle simulators. However, the great number of operational constraints that these devices and algorithms suffer, namely limited physical space, elevated costs, absence of sufficient power, difficulty of tuning and lack of standardized assessment methods, have hindered their widespread use. This work tries to clarify open questions in the field, such as: How important is MCA tuning? How much does size, number of DOF and power/latency matter? Can the absence of motion be better than poor motion cueing? What are the key factors that should be addressed to enhance the design of these devices? Although absolute certain answers cannot be given, this paper tries to clarify these research questions by performing massive experiments with simulated motion platforms of different types, sizes and powers. The information obtained from these experiments will be important to customize the design of real devices for this particular use. Ideally, subjective experiments with human experts would have been preferred. However, the use of simulated devices allows comparing many different motion platforms. In this paper, forty of these devices are simulated, optimized by means of a heuristic algorithm and compared with objective indicators in order to measure their relative performance using the classical MCA, something that would require an unreasonable amount of effort with real users and real devices. The obtained results show that MCA tuning is of the utmost importance in motion cueing. They also suggest that high power can usually compensate for lack of size and that a 6-DOF motion platform slightly improves the performance of a 3-DOF motion platform.
4 citations
TL;DR: This paper deals with identifying a method to perform a fast but reliable simulation of parallel mechanisms to be used for motion cueing generation using Laplacian polynomial transfer function models by means of using AM-FM bi-modulated signals as reference inputs.
4 citations
01 Jan 2019
TL;DR: It is of the utmost importance to analyze the requirements of each VR application before deciding upon this question, although, unlike audio-visual cues, there can be specific considerations for each particular solution that may suggest otherwise.
Abstract: This chapter deals with the problem of including motion cues in VR applications. From the challenges of this technology to the latest trends in the field, the authors discuss the benefits and problems of including these particular perceptual cues. First, readers will know how motion cues are usually generated in simulators and VR applications in general. Then, the authors list the major problems of this process and the reasons why its development has not followed the pace of the rest of VR elements (mainly the display technology), reviewing the motion vs. no-motion question from several perspectives. The general answer to this discussion is that motion cues are necessary in VR applications—mostly vehicle simulators—that rely on motion, although, unlike audio-visual cues, there can be specific considerations for each particular solution that may suggest otherwise. Therefore, it is of the utmost importance to analyze the requirements of each VR application before deciding upon this question.
4 citations
References
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01 Jun 1965
TL;DR: In this article, the authors describe a six-degree-of-freedom control with six motors, each having a ground abutment, for simulating flight conditions in the training of pilots.
Abstract: This paper describes a mechanism which has six degrees of freedom, controlled in any combination by six motors, each having a ground abutment. It is considered that by its particular arrangement, this mechanism may form an elegant design for simulating flight conditions in the training of pilots. Unlike most simulators, it has no fixed axes relative to the ground, and therefore within the limits of amplitude of the design it can truly simulate the conditions of banking by carrying the simulation of control surfaces into the axes of the new attitude.Variations in control arrangements are described and their respective design merits considered.Other possible uses for this mechanism are mentioned, including automation of production.
2,341 citations
Book•
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31 Jul 2000
TL;DR: This book presents a complete synthesis of the latest results on the possible mechanical architectures, analysis and synthesis of this type of mechanism, Parallel robots, which are becoming increasingly popular in the field of machine-tool industry.
Abstract: Parallel robots are closed-loop mechanisms presenting very good performances in terms of accuracy, velocity, rigidity and ability to manipulate large loads. They have been used in a large number of applications ranging from astronomy to flight simulators and are becoming increasingly popular in the field of machine-tool industry. This book presents a complete synthesis of the latest results on the possible mechanical architectures, analysis and synthesis of this type of mechanism. It is intended to be used by students (with over 150 exercises and numerous internet addresses), researchers (with over650 references and anonymous ftp access to the code of some algorithms presented in this book) and engineers (for which practical results, mistakes to avoid,and applications are presented). Since the publication of the first edition (2000) there has been an impressive increase in terms of study and use of this kind of structure that are reported in this book. This second edition has been completely overhauled. The initial chapter on kinematics has been split into Inverse Kinematics and Direct Kinematics. A new chapter on calibration was added. The other chapters have also been rewritten to a large extent.The reference section has been updated to include around 45% new works that appeared after the first edition.
2,137 citations
Additional excerpts
...Over the last years, the advantages of parallel manipulators (PM) in terms of high accuracy, velocity, stiffness and payload capacity over the serials, have promoted their use not only for motion simulation but also for a wide variety of applications (Merlet, 2006)....
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Book•
08 Feb 1999
TL;DR: In this paper, Jacobian analysis of serial manipulators and Jacobian Jacobian Analysis of parallel manipulators is used to analyze the structural and stiffness properties of a serial manipulator.
Abstract: Position Analysis of Serial Manipulators Position Analysis of Parallel Manipulators Jacobian Analysis of Serial Manipulators Jacobian Analysis of Parallel Manipulators Statics and Stiffness Analysis Wrist Mechanisms Tendon-Driven Manipulators Dynamics of Serial Manipulators Dynamics of Parallel Manipulators Appendices Index
1,744 citations
TL;DR: A review of the literature on the six-degree-of-freedom parallel manipulator commonly known as the Stewart platform can be found in this article, where the authors highlight the distinctions of this class from the conventional serial robot manipulators and the novel perspectives that are necessary for the analysis and design of the Stewart platforms in particular and parallel manipulators in general.
637 citations
"Optimization of 3-DOF parallel moti..." refers methods in this paper
...Several researchers have addressed the analysis of the Gough-Stewart platform, developing kinematic and dynamic analyses (Cheng et al., 2003; Dasgupta and Mruthyunjaya, 2000), presenting algorithms for solving the forward kinematics problem (Korobeynikov and Turlapov, 2005; Liu et al....
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...Several researchers have addressed the analysis of the Gough-Stewart platform, developing kinematic and dynamic analyses (Cheng et al., 2003; Dasgupta and Mruthyunjaya, 2000), presenting algorithms for solving the forward kinematics problem (Korobeynikov and Turlapov, 2005; Liu et al., 1993),…...
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TL;DR: In this paper, the structural characteristics associated with parallel manipulators are investigated and a class of 3 degree-of-freedom (3-UPUF) manipulators with only translational degrees of freedom are identified.
Abstract: The structural characteristics associated with parallel manipulators are investigated. Using these characteristics a class of 3 degree-of-freedom parallel manipulators are enumerated. Several parallel manipulators with only translational degrees of freedom are identified and the 3-UPU parallel manipulator is chosen for design analysis and optimization. The kinematics of this 3-UPU parallel manipulator is studied. Two geometric conditions that lead to pure translational motion of the moving platform are described. Due to the simple kinematic structure, the inverse kinematics yields two equal and opposite limb lengths whereas the direct kinematics produces two possible manipulator postures with one being the mirror image of the other. The Jacobian matrix is derived and several singular conditions are discussed. Furthermore the conditions for existence of an isotropic point within the workspace are discussed and equations to compute the isotropic configurations of a 3-UPU manipulator are derived. Finally, we undertake architecture optimization and show that certain values of design variables maximize the global condition index of the 3-UPU manipulator.
306 citations
"Optimization of 3-DOF parallel moti..." refers methods in this paper
...Many 3-DOF translational PM and their kinematic analysis have been proposed with various topologies, like 3-UPU (L. Tsai and Joshi, 2000), 3-URC (Di Gegorio, 2001), 3-RRC (Zhang et al., 2009), 3-CRR (Kong and Gosselin, 2002), 3-RPC (Callegari and Tarantini, 2003), a Cartesian parallel manipulator…...
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