A crucially important aspect for mission-critical robotic operations is ensuring as best as possible that an autonomous system be able to complete its task. In a project for the Defense Threat Reduction Agency (DTRA) we are developing methods to provide such guidance, specifically for counter-Weapons of Mass Destruction (C-WMD) missions. In this paper, we describe the scenarios under consideration, the performance measures and metrics being developed, and an outline of the mechanisms for providing performance guarantees.

In this paper, we present a whole-body control framework for Wheeled Inverted Pendulum (WIP) Humanoids. WIP Humanoids are redundant manipulators dynamically balancing themselves on wheels. Characterized by several degrees of freedom, they have the ability to perform several tasks simultaneously, such as balancing, maintaining a body pose, controlling the gaze, lifting a load or maintaining end-effector configuration in operation space. The problem of whole-body control is to enable simultaneous performance of these tasks with optimal participation of all degrees of freedom at specified priorities for each objective. The control also has to obey constraint of angle and torque limits on each joint. The proposed approach is hierarchical with a low level controller for body joints manipulation and a high-level controller that defines center of mass (CoM) targets for the low-level controller to control zero dynamics of the system driving the wheels. The low-level controller plans for shorter horizons while considering more complete dynamics of the system, while the high-level controller plans for longer horizon based on an approximate model of the robot for computational efficiency.

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Safe control for inherently unstable systems such as quadrotors is crucial. Imposing multiple dynamic constraints simultaneously on the states for safety regulation can be a challenging problem. In this paper, we propose a quadratic programming (QP) based approach on a cascaded control architecture for quadrotors to enforce safety. Safety regions are constructed using control barrier functions (CBF) while explicitly considering the nonlinear underactuated dynamics of the quadrotor. The safety regions constructed using CBFs establish a non-conservative forward invariant safe region for quadrotor navigation. Barriers imposed across the cascaded architecture allow independent safety regulation in the quadrotor's altitude and lateral domains. Despite barriers appearing in a cascaded fashion, we show preservation of safety for quadrotor motion in SE(3). We demonstrate the feasibility of our method on a quadrotor in simulation with static and dynamic constraints enforced on the position and velocity spaces simultaneously.

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Autonomous robots offer the potential to conduct Counter-Weapons of Mass Destruction (C-WMD) missions in an efficient and robust manner. However, to leverage this potential, a mission designer needs to be able to determine how well a robot system will operate in the noisy and uncertain environments that a C-WMD mission may require. We are developing a software framework for verification of performance guarantees for C-WMD missions based on the MissionLab software system and a novel process algebra approach to representing robot programs and operating environments.In this paper, we report on our initial research for the Defense Threat Reduction Agency (DTRA) in understanding what is required from a performance guarantee to give a mission designer the information necessary to understand how well a robot program will perform in a specific environment. We link this to prior work on metrics for robot performance. Using a simple mission scenario, we explore the implications of uncertainty in the four components of the problem: the robot program, and the sensors, actuators and environment with which the program is executed.

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