Extending Discrete Verbal Commands with Continuous Speech for Flexible Robot Control

Speech is a direct and intuitive method to control a robot. While natural speech can capture a rich variety of commands, verbal input is poorly suited to finer grained and real-time control of continuous actions such as short and precise motion commands. For these types of operations, continuous non-verbal speech is more suitable, but it lacks the naturalness and vocabulary breadth of verbal speech. In this work, we propose to combine the two types of vocal input by extending the last vowel of a verbal command to support real-time and smooth control of robot actions. We demonstrate the effectiveness of this novel hybrid speech input method in a beverage-pouring task, where users instruct a robot arm to pour specific quantities of liquid into a cup. A user evaluation reveals that hybrid speech improves on simple verbal-only commands.