A Time-Driven Workflow Scheduling Strategy for Reasoning Tasks of Autonomous Driving in Edge Environment

In various time-slots, the real-time reasoning tasks generated by autonomous vehicles are scheduled within tolerance time, which is the key problem to be solved in autonomous driving. Tasks are traditionally scheduled on the on-board unit (OBU), which leads to long completion time of tasks. Heuristic algorithms are widely used in task scheduling problems, which usually causes to premature convergence. Scheduling tasks in edge environment can effectively reduce completion time of tasks. In this paper, a workflow scheduling strategy was designed in edge environment according to the difference of reasoning tasks and the changes of edge nodes in various time-slots. Firstly, the model of Markov decision process (MDP) was built to describe the problem scenario, and the completion time of reasoning tasks was calculated by the workflow scheduling algorithm. Secondly, the Q-learning algorithm based on simulated anealing (SA-QL) was proposed to optimize the completion time of reasoning tasks. Finally, the performance of reinforcement learning algorithms based on simulated annealing (SA-RL) and particle swarm optimization (PSO) algorithm were comprehensively displayed from four perspectives: effectiveness, feasibility, exploration and convergence. The experimental results show that both SA-RL algorithms and PSO algorithm have good performance in feasibility and effectiveness. TD(0) algorithms have better performance of exploration and TD() algorithms have that of convergence.