Hello! I'm working on a robotics project but I'm a bit unsure about sensor selection. What criteria should I consider when choosing a sensor? For example, how important are factors like accuracy, power consumption, and response time, and how can they be evaluated? What do you all focus on in your projects? Do you prefer different sensors for different applications?
How do you choose sensors for robotics projects?
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There will always need to be a balance between sensitivity and response time since they are directly related. For example, an ultrasonic sensor with a range of 3-400 cm (LJ) has a response time of 31 ms, while laser distance sensors (e.g., VL53L0X) can drop to as low as 30 µs—but the margin of error increases to 5% below 5 cm. If your project involves tracking the position of a moving robotic arm with 1 mm precision, a contactless laser would be the better choice; however, for a high-energy drone project where battery life drops to 2-3 hours, a 20-30 ms ultrasonic sensor might be the smarter option.
You should also evaluate power consumption and application synchronization together. A BNO055 (9-axis gyroscopic sensor) module running over I2C/SPI on an ESP32-based robot draws 4.3 mA in active mode—meaning a 1000 mAh battery would last 232 hours. But if your project uses six continuously running HC-SR04 ultrasonic sensors (15 mA each), you’ll need to put the system into sleep mode and optimize sensor synchronization. The key here is calculating the sensor’s "active window duration" and adjusting the MCU’s sleep time accordingly.
In some projects, noise resistance and operating temperature can also dictate sensor selection. In an industrial robotic system, infrared sensors (e.g., Sharp GP2Y0A21YK) may give misleading results due to dust and light pollution—whereas capacitive sensors (e.g., MPR121) perform more stably in such environments. Conversely, in a laboratory setting for a micro-robot, an ultra-high-precision optical encoder (e.g., AS5600) with 0.1% accuracy might be preferred. Ultimately, sensor selection is an equation—one that must always be recalculated based on the goal, environment, and other system components.