Potential Field Navigation of High Speed Unmanned Ground Vehicles on Uneven Terrain

2006 ◽  
Author(s):  
S. Shimoda ◽  
Y. Kuroda ◽  
K. Iagnemma
Keyword(s):  
Potential Field ◽  
High Speed ◽  
Unmanned Ground Vehicles ◽  
Ground Vehicles ◽  
Uneven Terrain

High-speed navigation of unmanned ground vehicles on uneven terrain using potential fields

Robotica ◽  
2007 ◽  
Vol 25 (4) ◽  
pp. 409-424 ◽  
Author(s):  
Shingo Shimoda ◽  
Yoji Kuroda ◽  
Karl Iagnemma
Keyword(s):  
Potential Field ◽  
High Speed ◽  
Longitudinal Velocity ◽  
Unmanned Ground Vehicles ◽  
Performance Bounds ◽  
Ground Vehicles ◽  
Computationally Efficient ◽  
Field Methods ◽  
Local Maxima ◽  
Natural Terrain

SUMMARYMany applications require unmanned ground vehicles (UGVs) to travel at high speeds on sloped, natural terrain. In this paper, a potential field-based method is proposed for UGV navigation in such scenarios. In the proposed approach, a potential field is generated in the two-dimensional “trajectory space” of the UGV path curvature and longitudinal velocity. In contrast to traditional potential field methods, dynamic constraints and the effect of changing terrain conditions can be easily expressed in the proposed framework. A maneuver is chosen within a set of performance bounds, based on the local potential field gradient. It is shown that the proposed method is subject to local maxima problems, rather than local minima. A simple randomization technique is proposed to address this problem. Simulation and experimental results show that the proposed method can successfully navigate a small UGV between predefined waypoints at speeds up to 7.0 m/s, while avoiding static hazards. Further, vehicle curvature and velocity are controlled during vehicle motion to avoid rollover and excessive side slip. The method is computationally efficient, and thus suitable for onboard real-time implementation.

Experimental research on the muzzle response characteristics of small unmanned ground vehicles with small arms

2021 ◽  
pp. 095440622110570
Author(s):  
Yugang Ding ◽  
Kedong Zhou ◽  
Lei He ◽  
Haomin Yang
Keyword(s):  
High Speed ◽  
Threshold Function ◽  
Measurement Unit ◽  
Unmanned Ground Vehicles ◽  
Vehicle Speed ◽  
Ground Vehicles ◽  
Small Arms ◽  
Inertial Measurement ◽  
Variable Threshold ◽  
Response Characteristics

The muzzle response is the main feature affecting the firing accuracy of weapons. To research the muzzle response characteristics of small unmanned ground vehicles with small arms (SUGVsSA) during shooting, this paper designs a test method that combines an inertial measurement system (IMS) with a high-speed photogrammetric system (HSPS) to measure the muzzle response. That is, an inertial measurement unit (IMU) is fixed onto the gun body to record the three-dimensional angular motion of the barrel; meanwhile, a high-speed camera is used to capture the characteristic markers of the unmanned ground vehicle from the side. After data processing, the muzzle response curves during four consecutive firings when the vehicle is running at different speeds and firing angles are obtained. Considering the presence of noise in muzzle response signals, the wavelet threshold de-noising (WTD) algorithm based on a novel variable threshold function is used to de-noise the test signal. The processing results demonstrate that the WTD algorithm based on the novel variable threshold function can not only suppress noise in the muzzle response signal but also retain the local details of the signal. The combination of the IMS and HSPS complements the muzzle response data and can comprehensively and accurately reflect the muzzle response characteristics of SUGVsSA. As the vehicle speed and firing angle increase, the muzzle vibration intensifies, only when the vehicle speed is 0.3 m/s, and the muzzle maximum elevation angle displacement after each firing decreases when it is stationary. The results presented in this paper may provide a workable reference for understanding the muzzle response characteristics of SUGVsSA and evaluating the firearm compatibility of other unmanned systems.

Road Bank Estimation on Uneven Terrain for Unmanned Ground Vehicles

2010 ◽  
Author(s):  
Lowell S. Brown ◽  
Jeremy J. Dawkins ◽  
Ryan S. Hill ◽  
David M. Bevly
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Unmanned Ground Vehicles ◽  
Ground Vehicles ◽  
Bank Angle ◽  
The Road ◽  
Uneven Terrain ◽  
Suspension Geometry ◽  
Vehicle Information

Knowledge of non-negligible bank angle is important for preventing rollover on uneven terrain. This article shows the effect of uneven terrain on rollover and explores a method to calculate the bank of the uneven terrain. An Extended Kalman Filter (EKF) is implemented to estimate the total roll of the vehicle. Information on the relative roll of the vehicle is acquired from suspension geometry and suspension deflections. The combination of EKF estimated roll and measured suspension deflections yields an estimate of the road bank angle.

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