Sensor

From FIRSTwiki

The Control System Logic of a Control System Closed loop PID controller Open loop Parts of a Control System Computer Robot Controller 2009 RC 2006 RC 2004 RC 2003 RC 2000 RC 1996 RC 1993 RC Robovation Input Operator Interface Joystick Output Victor 884 Spike Sensors Encoder Accelerometer Light sensor IR sensor Gyro CMUcam2

A sensor is a device that detects, or senses, the surrounding environment. In terms of robotics, and specifically FIRST, sensors enable the robot to better understand what is around it and how to react. The types of sensors used in FIRST are electrical, meaning that they send signals to the Robot Controller that is then converted into some value for use by the program. There are two main types of sensors, analog and digital. An analog sensor, such as a potentiometer, will have a value in the range of 0 to 1023 (10 bits). A digital sensor, such as a limit switch, is much more limited, only having off and on states, represented by 0 and 1.

Sensors are important aspects of programming, allowing truly complex robots that can react intelligently to dynamic situations. The use of advanced sensors is often necessary to devlop an effective autonomous mode, though many other uses are possible. Sensors can count the number of rotations of a particular wheel and then the program can adjust speed based on this information; sensors can determine whether some apendage is fully extended, and then shut off power to a motor; sensors can allow the robot to avoid objects that the robot operator might not see.

The sensors included in the kit of parts are:

• IR sensor
• Banner sensor
• Gyroscope
• Current sensor
• Pressure sensor
• Accelerometer
• A vision system, currently the CMUcam2.

See electronics rules for information on where and which sensors may be bought, and the price limit on them.

Resources

• Dean Kamen talks about sensors
• Digikey homepage