• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.221-232
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• 2020

In a four-wheel independent drive platform, four wheels and motors are connected directly, and the rotation of the motors generates the power of the platform. It uses a skid steering system that steers based on the difference in rotational power between wheel motors. The platform can control the speed of each wheel individually and has excellent mobility on dirt roads. However, the difficulty of the straight-running is caused due to torque distribution variation in each wheel's motor, and the direction of rotation of the wheel, and moving direction of the platform, and the difference of the platform's target direction. This paper describes an algorithm to detect the slip generated on each wheel when a four-wheel independent drive platform is traveling in a harsh environment. When the slip is detected, a compensation control algorithm is activated to compensate the torque of the motor mounted on the platform to improve the trajectory tracking performance of the platform. The four-wheel independent drive platform developed for this study verified the algorithm. The wheel slip detection and the compensation control algorithm of the platform are expected to improve the stability of trajectory tracking.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.2
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• pp.185-190
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• 2016

This paper deals with analysis of the characteristics of mobile robot's motion by automatic detection of markers on a robot using a camera. Analysis of motion behaviors according to parameters is important in developing control algorithm for robot operation or autonomous navigation. For this purpose, we use four chessboard patterns on the robot. Their location on the robot is adjusted to be on single plane. Homography is used to compute the actual amount of movement of the robot. Presented method is tested using P3-AT robot and it gives reliable results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.905-912
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• 2011

In order to protect equipment such as controllers, it is important to improve the driving stability of $6{\times}6$ skidsteering vehicles driven on rough roads. The estimation and improvement of the driving stability should be based on the vertical acceleration, roll acceleration, and pitch acceleration. These variables will be used to achieve multivariable control and increase the vehicle driving stability. In this study, to improve vehicle stability by reducing the vertical acceleration, roll angular acceleration, and pitch angular acceleration, the skyhook control method is employed to control MR(Magnetorheological) dampers equipped with the vehicle. The proposed control system is tested in multibody dynamic simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.599-605
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• 2017

For an unmanned vehicle to be driven on the off-road terrain, it is necessary to consider the vehicle's stability. This paper suggests a path tracking controller for simulation of real-time vehicle stability analysis. The path tracking controller uses the preview distance to track the given trajectory. The disturbance moment is estimated using the yaw moment observer, and this information is used for compensation in the yaw moment control. On a curved path, the vehicle's desired velocity is determined from the curvature of the path. Because the vehicle is equipped with six independent motor driven wheels, the driving torques are distributed on all the wheels. The effectiveness of the path tracking controller is verified using ADAMS/MATLAB co-simulation.