The general problem of planning feasible trajectories for multimodal robots is still an open challenge. This paper presents a whole-body trajectory optimisation approach that addresses this challenge by combining methods and tools developed for aerial and legged robots. First, robot models that enable the presented whole-body trajectory optimisation framework are presented. The key model is the so-called robot centroidal momentum, the dynamics of which is directly related to the models of the robot actuation for aerial and terrestrial locomotion. Then, the paper presents how these models can be employed in an optimal control problem to generate either terrestrial or aerial locomotion trajectories with a unified approach. The optimisation problem considers robot kinematics, momentum, thrust forces and their bounds. The overall approach is validated using the multimodal robot iRonCub, a flying humanoid robot that expresses a degree of terrestrial and aerial locomotion. To solve the associated optimal trajectory generation problem, we employ ADAM, a custom-made open-source library that implements a collection of algorithms for calculating rigid-body dynamics using CasADi.
翻译:规划多式机器人可行轨迹的一般问题仍是一个公开的挑战。 本文展示了一种全机轨迹优化方法,通过结合为空中和腿部机器人开发的方法和工具来应对这一挑战。 首先, 展示了能够实现所展示的全机轨迹优化框架的机器人模型。 关键模型是所谓的机器人环球动力, 其动态与机器人为空中和地面移动启动的模型直接相关。 然后, 本文介绍了如何将这些模型用于最佳控制问题, 以统一的方法生成地面或空中移动轨迹。 优化问题考虑了机器人运动、 动力、 推力 及其界限。 总体方法使用多式机器人 iRonCub 进行验证, 这是一种显示某种程度的地面和空中移动动动能的飞行人类机器人。 为了解决相关的最佳轨迹生成问题, 我们使用ADAM, 一个定制的开放源图书馆, 用于使用 CasADIDi 来收集计算硬体动态的算法。