Sensor Selection for Robotics: Optimising Feedback and Control
Selecting the right sensors is a design decision that affects control accuracy, system stability, and long-term reliability. In robotics, sensors provide the feedback loop that determines how well actuators follow commands under real-world conditions. If the feedback is noisy, slow, or imprecise, even the best control algorithms will struggle. Selecting the right sensor, with the correct accuracy, speed, robustness and integration, often makes the difference between a robot that works only on the test bench and one that performs reliably in a real-world environment.
Robotic Sensors in the Control Loop
Robotic systems rely on closed-loop control. Position sensors, encoders, and force sensors provide real-time data to motion controllers, enabling precise speed and torque regulation. Without this feedback, servo systems drift, assembly forces become unpredictable, and safety functions lose reliability. Selecting sensors isn’t about catalogue specs – it’s about matching performance to dynamic requirements.
Engineering Considerations for Sensor Selection
- Measurement Objective
What is the task?Positioning, precise insertion, force-sensitive assembly, navigation, mobile movement? Define what you need. For example, monitoring cutter speed in an autonomous mower requires a sensor that handles outdoor conditions and variable loads.
- Resolution and Linearity
Do you need sub-millimetre position accuracy or only coarse feedback? High-precision tasks like component insertion demand sensors with fine resolution and minimal non-linearity. Force sensors with stable output prevent overloading delicate parts. - Response Time
In fast-moving systems, latency can destabilise the control loop. Sensors must update fast enough to keep the control loop stable and responsive. - Environmental Tolerance
Consider IP ratings, temperature range, and resistance to vibration or hydraulic pressure. Outdoor and industrial environments demand rugged designs. - Integration
Sensors should interface seamlessly with PLCs, servo drives, or motion controllers using standard analogue signals or digital communication protocols commonly used in automation systems.
Long-term stability, drift, and maintenance requirements should also be considered.
Examples in Practice
- Autonomous Lawn Mower: Gear tooth sensors measure cutter speed for closed-loop control under varying grass density.
- Component Insertion: Force sensors provide feedback for adaptive assembly, reducing scrap and improving quality.
- Minimally invasive surgery: Torque sensors integrated into motors that support the precise control of endoscopic instruments during surgical procedures.
Sensor selection is about understanding what the robot must do now and over its lifetime. Evaluate resolution, response time, environmental resilience, and integration. Then choose technologies that deliver reliability and flexibility for advanced robotics.
Ready to design smarter robotics? Businesses within Variohm Group manufacture and supply a wide range of position, force and torque sensors for advanced robotics and industrial automation – standard or custom-built to your specifications. Contact our team today at