Autonomous Mobile Robots and Multi-Robot Systems

2Basic Perception

Simon Lineykin

Sensors are required robot accessories that enable the robot to collect and process external as well as internal information. External information may include temperature, illumination conditions, distance to obstacle, magnetic field intensity, and more, while internal information has to do with the motor's electrical current, wheel revolution speed, battery voltage, arms position, etc. There are dozens of different types of sensors. A good classification is given by Tönshoff et al. (2008), Siegwart et al. (2011), and Dudek and Jenkin (2010). This chapter will only describe those types of sensors that are commonly used in robotics.

2.1 Basic Scheme of Sensors

Robot developers refer to both a sensing element and a sensing unit as a sensor. Sensing units are used in robotics for measuring, alarming, and control of processes. The sensing element, which is the principal component of a sensing unit, converts a controlled parameter (pressure, temperature, flow rate, concentration, frequency, velocity, displacement, voltage, current, etc.) into a signal (e.g., electrical, optical, pneumatic, etc.); see Zumbahlen (2007). Since the electrical signal is the most convenient for processing and digitizing, the vast majority of sensitive elements have electrical signal at the output.

Sometimes a sequence of sensing elements is used to provide an electrical output signal. The use of such sequences of sensing elements is common in exotic sensors as well ...