Driving Control of Car-Like Robots by Path-Generating Regulator

Mathematical Problems in Engineering

Kazama

et al. 2014

Self Cite

The improved path-generating regulator (PGR) is proposed to path track the circle/arc passage for two-wheeled robots. The PGR, which is a control method for robots so as to orient its heading toward the tangential direction of one of the curves belonging to the family of path functions, is applied to navigation problem originally. Driving environments for robots are usually roads, streets, paths, passages, and ridges. These tracks can be seen as they consist of straight lines and arcs. In the case of small interval, arc can be regarded as straight line approximately; therefore we extended the PGR to drive the robot move along circle/arc passage based on the theory that PGR to track the straight passage. In addition, the adjustable look-ahead method is proposed to improve the robot trajectory convergence property to the target circle/arc. The effectiveness is proved through MATLAB simulations on both the comparisons with the PGR and the improved PGR with adjustable look-ahead method. The results of numerical simulations show that the adjustable look-ahead method has better convergence property and stronger capacity of resisting disturbance.

Section: The Pgr Along Circle/arc Passage Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Improved Path-Generating Regulator for Two-Wheeled Robots to Track the Circle/Arc Passage

Dai

Mathematical Problems in Engineering

Kazama

et al. 2014

Self Cite

“…When x > 0, the space between the two surfaces is defined as D2. According to a previous report (Taruumi, et al, 2013). When the initial pose is in D1, the robot moves forward and converges to the origin, when the initial pose is in D2, the robot moves backward and converges to the origin.…”

Section: Pgr For Car-like Robotsmentioning

confidence: 99%

“…This method has been extended to car-like robots. The convergent regions have been discussed (Taruumi, et al, 2013). The convergent regions are surrounded by singular points.…”

Section: Introductionmentioning

confidence: 99%

Steering angle saturation analysis in PGR under feedback gain switching strategy for car-like robots

Dai

Mechanical Engineering Journal

Kazama

et al. 2014

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This work analyzes the influence of steering angle saturation to the convergent property in the Path-generating Regulator (PGR) under the feedback gain switching strategy for car-like robots. The PGR control method carries out asymptotic convergence to a given path function group. It has been extended to car-like robots, and its convergent region has been expanded by the feedback gain switching strategy. However, under this strategy, when the robot restarts after the feedback gain switches, the command of the steering angle tends to be close to ±π/2 rad, which might exceed the maximum steering angle. This phenomenon causes steering angle saturation. The robot then drives along the minimum turning circle. In this paper, the convergent property of the robot under steering angle saturation is investigated first. Results show that the convergent property is related strongly to the number of singular points, which depends on the center location of the minimum turning circle. Then the convergent properties at different locations are clarified through region division. Moreover, an extended feedback gain switching strategy method is proposed to change the convergent property in the specific region. Based on simulation and experiment results, we summarize the convergent property related to the region and verify the proposed method.

Path-generating regulator for a car-like robot navigation considering necessity of observation

Otani

Transactions of the JSME (In Japanese)

Yoshida

2017

Self Cite

In this study, we discuss a problem to collect observation data with one mobile robot in extensive investigation field.When the measurement of observation data is carried out by the mobile robot, the setting of running-path and navigation are important for appropriate measurement. Usually reciprocating straight paths at even interval are employed to collect data with spatially uniform density. However it is possible that some area between the straight paths requires detailed measurement. The method proposed in this paper makes it possible that in ordinary situation the robot follows the straight path, in the proximity of the area with need of observation it leaves the straight path toward the area, after that returns to the preceding straight path. Recently the path-generating regulator (PGR) has been applied to a tracking problem along a straight passage for car-like robots. The PGR is a control method for a vehicle so as to orient its heading toward a tangent to one of the curves belonging to a family of path functions. In this paper, we append a property to the PGR tracking the straight passage to modify the target heading angle in accordance with necessity of observation and to realize the motion toward the area with need of observation. To confirm the efficiency of the proposed method, two types of simulations are performed. The first simulation shows how a level of necessity of observation and a range to the area changes the locus of the mobile robot. In the second simulation, the mobile robot is satisfactorily guided by the level of necessity of observation obtained from actual measured data in a survey site.