With the development of robotics, ground robots are no longer limited to planar motion. Passive height variation due to complex terrain and active height control provided by special structures on robots require a more general navigation planning framework beyond 2D. Existing methods rarely considers both simultaneously, limiting the capabilities and applications of ground robots. In this paper, we proposed an optimization-based planning framework for ground robots considering both active and passive height changes on the z-axis. The proposed planner first constructs a penalty field for chassis motion constraints defined in R3 such that the optimal solution space of the trajectory is continuous, resulting in a high-quality smooth chassis trajectory. Also, by constructing custom constraints in the z-axis direction, it is possible to plan trajectories for different types of ground robots which have z-axis degree of freedom. We performed simulations and realworld experiments to verify the efficiency and trajectory quality of our algorithm.

翻译：随着机器人技术的发展，地面机器人不再局限于平面运动。复杂地形引起的被动高度变化以及机器人特殊结构提供的主动高度控制，要求构建超越二维环境的通用导航规划框架。现有方法鲜少同时考虑这两个因素，限制了地面机器人的能力与应用范围。本文提出一种基于优化的规划框架，同时考虑地面机器人在z轴上的主动与被动高度变化。该规划器首先在R3空间内构建底盘运动约束的惩罚场，使轨迹最优解空间连续，从而生成高质量的平滑底盘轨迹。同时，通过在z轴方向构建自定义约束，可为具有z轴自由度的不同类型地面机器人规划轨迹。我们通过仿真与真实实验验证了算法的效率与轨迹质量。