Motion planning of an autonomous system with high-level specifications has wide applications. However, research of formal languages involving timed temporal logic is still under investigation. Furthermore, many existing results rely on a key assumption that user-specified tasks are feasible in the given environment. Challenges arise when the operating environment is dynamic and unknown since the environment can be found prohibitive, leading to potentially conflicting tasks where pre-specified timed missions cannot be fully satisfied. Such issues become even more challenging when considering time-bound requirements. To address these challenges, this work proposes a control framework that considers hard constraints to enforce safety requirements and soft constraints to enable task relaxation. The metric interval temporal logic (MITL) specifications are employed to deal with time-bound constraints. By constructing a relaxed timed product automaton, an online motion planning strategy is synthesized with a receding horizon controller to generate policies, achieving multiple objectives in decreasing order of priority 1) formally guarantee the satisfaction of hard safety constraints; 2) mostly fulfill soft timed tasks; and 3) collect time-varying rewards as much as possible. Another novelty of the relaxed structure is to consider violations of both time and tasks for infeasible cases. Simulation results are provided to validate the proposed approach.
翻译:对具有高规格的自主系统进行规划具有广泛的应用性。然而,对涉及时间逻辑的正规语言的研究仍在调查之中。此外,许多现有成果都依赖于一个关键假设,即用户指定的任务在特定环境中是可行的。当操作环境是动态的,而且由于环境可被认为令人望而却步,因而环境会变得令人望而却步,从而在预先规定的定时任务无法完全满足的情况下,导致可能相互冲突的任务。这些问题在考虑有时限的要求时变得更加困难。为了应对这些挑战,这项工作提出了一个控制框架,其中考虑到执行安全要求的困难限制和软性限制,以便能让任务放松。采用标准间时间逻辑(MITL)的规格来处理有时限的限制。通过构建一个宽松的时空产品自动图,在线行动规划战略与一个重新缩减的视野控制器相结合,以产生政策,实现多个目标,从而降低优先次序的顺序(1) 正式保证对硬性安全限制的满足;2) 多数完成软性的时间任务;和3) 尽可能收集时间变化的奖赏。一个新颖的办法是考虑的是,简化结构的另一个新颖之处是考虑违反时间和任务的情况,即考虑对不可行案例进行验证。