# Dynamic Walking with Compliance on a Cassie Bipedal Robot

## TL;DR

This paper presents a method for generating and implementing dynamic, compliant walking controllers for the Cassie bipedal robot, demonstrating reliable outdoor and indoor terrain traversal with minimal tuning.

## Contribution

It introduces a full-body dynamics-based control approach for dynamic walking with compliance, bridging simulation and real-world implementation effectively.

## Key findings

- Successful real-world walking on various terrains
- Minimal tuning required for hardware implementation
- Consistent control performance across simulation and experiments

## Abstract

The control of bipedal robotic walking remains a challenging problem in the domains of computation and experiment, due to the multi-body dynamics and various sources of uncertainty. In recent years, there has been a rising trend towards model reduction and the design of intuitive controllers to overcome the gap between assumed model and reality. Despite its viability in practical implementation, this local representation of true dynamics naturally indicate limited scalibility towards more dynamical behaviors. With the goal of moving towards increasingly dynamic behaviors, we leverage the detailed full body dynamics to generate controllers for the robotic system which utilizes compliant elements in the passive dynamics. In this process, we present a feasible computation method that yields walking trajectories for a highly complex robotic system. Direct implementation of these results on physical hardware is also performed with minimal tuning and heuristics. We validate the suggested method by applying a consistent control scheme across simulation, optimization and experiment, the result is that the bipedal robot Cassie walks over a variety of indoor and outdoor terrains reliably.