Optimal Path Planning for Helical Gear Profile Inspection with Point Laser Triangulation Probes

2000 ◽  
Vol 123 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Kevin B. Smith ◽  
Yuan F. Zheng

New commercial Point Laser Triangulation (PLT) probes enable Coordinate Measuring Machines (CMMs) to take faster, noncontact, accurate measurements. In this paper, we address how to apply this technology to inspect helical gears. Traditionally, gears are inspected with slow, costly, and dedicated machines. The proposed flexible inspection system with a fast measuring probe can significantly reduce capital equipment costs and inspection times. Integrating PLT probes on CMMs has been limited partly because of the difficulty in generating optimal inspection paths, and partly because of the highly reflective gear surfaces. Complex sensor-to-surface orientation and obstacle-avoidance requirements of these unique probes are the main cause of the difficulty. This paper presents a geometrical approach for obtaining an optimal path plan for helical gear profile inspection with PLT probes. Models for the orientation parameters and the allowable operating regions for the PLT probe are developed. A collision avoidance strategy is also presented. Although this new method was developed and demonstrated while creating an optimal path plan for inspecting helical gears, the developed models and principles can also be applied to optimal inspection plan generation for other parts.

Procedia CIRP ◽  
2021 ◽  
Vol 96 ◽  
pp. 324-329
Author(s):  
Frederik Wulle ◽  
Max Richter ◽  
Christoph Hinze ◽  
Alexander Verl

Author(s):  
Ahmed Barnawi ◽  
Prateek Chhikara ◽  
Rajkumar Tekchandani ◽  
Neeraj Kumar ◽  
Mehrez Boulares

2021 ◽  
Vol 9 (4) ◽  
pp. 405
Author(s):  
Raphael Zaccone

While collisions and groundings still represent the most important source of accidents involving ships, autonomous vessels are a central topic in current research. When dealing with autonomous ships, collision avoidance and compliance with COLREG regulations are major vital points. However, most state-of-the-art literature focuses on offline path optimisation while neglecting many crucial aspects of dealing with real-time applications on vessels. In the framework of the proposed motion-planning, navigation and control architecture, this paper mainly focused on optimal path planning for marine vessels in the perspective of real-time applications. An RRT*-based optimal path-planning algorithm was proposed, and collision avoidance, compliance with COLREG regulations, path feasibility and optimality were discussed in detail. The proposed approach was then implemented and integrated with a guidance and control system. Tests on a high-fidelity simulation platform were carried out to assess the potential benefits brought to autonomous navigation. The tests featured real-time simulation, restricted and open-water navigation and dynamic scenarios with both moving and fixed obstacles.


Author(s):  
R. G. Munro ◽  
L Morrish ◽  
D Palmer

This paper is devoted to a phenomenon known as corner contact, or contact outside the normal path of contact, which can occur in spur and helical gear transmission systems under certain conditions. In this case, a change in position of the driven gear with respect to its theoretical position takes place, thus inducing a transmission error referred to here as the transmission error outside the normal path of contact (TEo.p.c). The paper deals with spur gears only, but the results are directly applicable to helical gears. It systematizes previous knowledge on this subject, suggests some further developments of the theory and introduces the novel phenomenon of top contact. The theoretical results are compared with experimental measurements using a single flank tester and a back-to-back dynamic test rig for spur and helical gears, and they are in good agreement. Convenient approximate equations for calculation of TEo.p.c suggested here are important for analysis of experimental data collected in the form of Harris maps. This will make possible the calculation of tooth stiffness values needed for use in theoretical models for spur and helical gear transmission systems.


Author(s):  
Zhe Zhang ◽  
Jian Wu ◽  
Jiyang Dai ◽  
Cheng He

For stealth unmanned aerial vehicles (UAVs), path security and search efficiency of penetration paths are the two most important factors in performing missions. This article investigates an optimal penetration path planning method that simultaneously considers the principles of kinematics, the dynamic radar cross-section of stealth UAVs, and the network radar system. By introducing the radar threat estimation function and a 3D bidirectional sector multilayer variable step search strategy into the conventional A-Star algorithm, a modified A-Star algorithm was proposed which aims to satisfy waypoint accuracy and the algorithm searching efficiency. Next, using the proposed penetration path planning method, new waypoints were selected simultaneously which satisfy the attitude angle constraints and rank-K fusion criterion of the radar system. Furthermore, for comparative analysis of different algorithms, the conventional A-Star algorithm, bidirectional multilayer A-Star algorithm, and modified A-Star algorithm were utilized to settle the penetration path problem that UAVs experience under various threat scenarios. Finally, the simulation results indicate that the paths obtained by employing the modified algorithm have optimal path costs and higher safety in a 3D complex network radar environment, which show the effectiveness of the proposed path planning scheme.


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