Real-time trajectory planning method for unmanned vehicles based on speed obstacles

Abstract

The invention discloses an unmanned ground vehicle real-time track planning method based on a speed impediment. The method comprises the following steps of: 1, constructing a node n<i, j> of an anti-collision mobile search tree on the basis of the current position of an unmanned ground vehicle A; 2, constructing a reachable anti-collision speed set RAV<j>(t) of the unmanned ground vehicle A on the basis of the speed of the unmanned ground vehicle A and the speed of an obstacle; 3, calculating the optimum speed (defined as in the description) of the current planning moment through a cubic polynomial smooth controllable unit; 4, setting a speed risk factor (defined as in the description); 5, selecting a new speed, i.e., an operational character o<i, j, l> at the moment t, on the basis of the reachable speed set RAV<j>(t) and the speed risk factor; 6, constructing a branch e<j, k> on the basis of the node n<i, j> and the operational character o<i, j, l>, and obtaining a node n<i+1, k> at the moment t<i+1> or the moment t+T<S>; and 7, if the n<1+i, k> node state is in a minimum neighborhood of the target state g, completing the algorithm, and otherwise, returning to the first step for cyclic calculation. The method provided by the invention is applicable to real-time track planning under various mobile conditions such as unmanned ground vehicle lane change, crossing turning and obstacle avoiding; the real-time performance and the high precision of the planning can be ensured under the condition of existence of a plurality of dynamic obstacles; and the requirements of the planning speed and the track smoothness can be met to the maximum degree.

Description

【Technical field】 [0001] The invention relates to the technical field of intelligent transportation systems, in particular to a real-time trajectory planning method in an unmanned driving system. 【Background technique】 [0002] Unmanned vehicles are not only an important part of the intelligent transportation system, but also a research hotspot in the field of mobile robot research. Trajectory planning methods for unmanned vehicles under static environmental conditions have achieved a lot of results, but trajectory planning in dynamic environments is much more complicated than trajectory planning in static environments, so there is no unified and effective planning method. [0003] Current approaches to solving trajectory planning problems in dynamic environments mainly fall into four categories. The first type of method is similar to the first type of static environment trajectory planning method, except that a one-dimensional time axis is added to the search space, and th...

AI Technical Summary

Problems solved by technology

The fourth type of method is to use the velocity information to directly determine the potential collision possibility, and plan directly in the configuration-velocity space through the exhaustive method or the intelligent search method. The advantage of this strategy is that it does not increase the dimension of the search space. However, when When there are many dynamic obstacles, the computational geometry method involved in this method has a large amount of calculation, and finding an efficient intelligent search method is the key to this type of method

Under the condition of multiple dynamic obstacles, most of the existing online trajectory planning methods for unmanned vehicles are difficult to balance the accuracy of the planning results and the computational efficiency of the planning process

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