On Radiation-Based Thermal Servoing: New Models, Controls, and Experiments

In this article, we introduce a new sensor-based control method that regulates (by means of robot motion) the temperature of objects that are subject to a radiative heat source. This valuable sensorimotor capability is needed in many industrial, dermatology, and field robot applications, and it is an essential component for creating machines with advanced thermomotor intelligence. To this end, we derive a geometric-thermal-motor model, which describes the relation between the robot's active configuration and the produced dynamic thermal response. We then use the model to guide the design of two new thermal servoing controllers (one model-based and one adaptive), and analyze their stability with Lyapunov theory. To validate our method, we report a detailed experimental study with a robotic manipulator conducting autonomous thermal servoing tasks. We show that the temperature of multiple objects with unknown thermophysical properties attached to the same end-effector can be effectively regulated by controlled robot motion. Although thermal sensing is a mature technology in many industrial thermal engineering applications, its use as a feedback signal for robot control has not been sufficiently studied in the literature. To the best of our knowledge, this is the first time that temperature regulation is formulated as a motion control problem for robots.