Feeling Their Way Around: Robot Sensors

Sep 22, 2013

Robotic sensors help to increase the robot's ability to sense environmental factors. The sensors are small, lightweight, and able to adjust where they are and what they are doing. There are a variety of robotic sensors available based on your application's exact needs.


Humans are capa­ble of sens­ing envi­ron­men­tal fac­tors around them and are aware of what each of their body parts is doing at any giv­en time, while robots are not afford­ed this lux­u­ry. Small, light­weight sen­sors help the robots adjust to where they are, what they are doing, and where their own parts are. Engi­neers increase the num­ber of sen­sors used on a robot as the robot gets more com­plex. A sin­gle task may require a com­bi­na­tion of dif­fer­ent sensors.

Light sen­sors detect light and cre­ate a volt­age dif­fer­ence. Pho­tore­sis­tor and pho­to­volta­ic cells are the most com­mon types of light sen­sors. Photoresistor’s resis­tance varies with change in light inten­si­ty and are eas­i­ly imple­ment­ed. Pho­to­volta­ic cells con­vert solar radi­a­tion into elec­tri­cal energy.

Sound sen­sors detect sound and return a volt­age pro­por­tion­al to the sound lev­el. The sen­sor is usu­al­ly a micro­phone, and can help even a sim­ple robot nav­i­gate based on the sound it receives. Com­plex robots can use a micro­phone for speech and voice recognition.

A push but­ton switch, lim­it switch, and tac­tile bumper are exam­ples of con­tact sen­sors. They are typ­i­cal­ly used for robots to avoid obsta­cles, and are trig­gered when phys­i­cal con­tact against oth­er objects is estab­lished. After an object is bumped, the sen­sor trig­gers the robot to reverse, turn, stop, etc. Touch screen smart phones and oth­er devices use a form of a con­tact sensor.

Instead of allow­ing the robot to make phys­i­cal con­tact with an obsta­cle, a prox­im­i­ty sen­sor can be installed so that the robot can detect the pres­ence of a near­by object with­in a giv­en dis­tance. A trans­mit­ter sends elec­tro­mag­net­ic radi­a­tion or elec­tro­sta­t­ic field, and the receiv­er ana­lyzes the return sig­nal for inter­rup­tions. Exam­ples of prox­im­i­ty sen­sors are infrared trans­ceivers, ultra­son­ic sen­sors, and photoresistors.

Indus­tri­al man­u­fac­tur­ers ben­e­fit from pres­sure sen­sors. Tac­tile pres­sure sen­sors are sen­si­tive to touch, force, and pres­sure. If the robot hand needs to apply a cer­tain amount of grip and pres­sure required to hold an object, the pres­sure sen­sor is the solution.

Posi­tion­ing sen­sors approx­i­mate the posi­tion of the robot; GPS is the most com­mon­ly used. Satel­lites trans­mit sig­nals and a receiv­er on the robot acquires these sig­nals to process. GPS sys­tems are ben­e­fi­cial for out­door robots. Dig­i­tal mag­net­ic com­pass and local­iza­tion are oth­er posi­tion­ing sensors.

When robots are required to work in extreme envi­ron­ments, a tem­per­a­ture sen­sor might be nec­es­sary. Tem­per­a­ture sen­sor ICs pro­vide volt­age dif­fer­ence for a change in temperature.

Robots​.com can help you incor­po­rate an indus­tri­al robot with robot­ic sen­sors. Con­tact us today on how to pick the right sen­sors for your facil­i­ty; online or at 8777626881.

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