Session
2026 Session 4
Location
Orem, UT
Start Date
5-4-2026 11:20 AM
Description
Isoperimetric robotic trusses offer promising solutions for lunar infrastructure due to their lightweight design and adaptability. However, motor failures in the harsh lunar environment can severely limit operational capabilities if not properly addressed. This paper presents a fault-tolerant control framework for an inflatable robotic truss that maintains functionality despite motor failures through three key contributions. First, we extend the kinematic optimization to handle arbitrary combinations of motor failures by imposing equality constraints to ensure failed actuators are not used. Second, we implement closed-loop position control using onboard encoder feedback and a forward kinematics-based state estimator, improving positional accuracy in the presence of disturbances. Third, we introduce discrete-time control barrier function (DTCBF) constraints that mathematically guarantee structural rigidity while maximizing workspace utilization—critical for reliable operation in sampled-data control systems. We validate our approach through simulation and hardware experiments on a 2D isoperimetric truss testbed. For a 2D configuration with 6 actuators, we demonstrate > 69% workspace preservation under single-motor failures and a > 25% improvement in tracking accuracy with closed-loop control. These results establish a foundation for resilient soft robotic systems capable of sustained operation in remote environments where repair is infrequent.
Fault-Tolerant, Rigidity-Preserving Control of Inflatable Truss Robots
Orem, UT
Isoperimetric robotic trusses offer promising solutions for lunar infrastructure due to their lightweight design and adaptability. However, motor failures in the harsh lunar environment can severely limit operational capabilities if not properly addressed. This paper presents a fault-tolerant control framework for an inflatable robotic truss that maintains functionality despite motor failures through three key contributions. First, we extend the kinematic optimization to handle arbitrary combinations of motor failures by imposing equality constraints to ensure failed actuators are not used. Second, we implement closed-loop position control using onboard encoder feedback and a forward kinematics-based state estimator, improving positional accuracy in the presence of disturbances. Third, we introduce discrete-time control barrier function (DTCBF) constraints that mathematically guarantee structural rigidity while maximizing workspace utilization—critical for reliable operation in sampled-data control systems. We validate our approach through simulation and hardware experiments on a 2D isoperimetric truss testbed. For a 2D configuration with 6 actuators, we demonstrate > 69% workspace preservation under single-motor failures and a > 25% improvement in tracking accuracy with closed-loop control. These results establish a foundation for resilient soft robotic systems capable of sustained operation in remote environments where repair is infrequent.