Sensors, I/O & Vision Systems Flashcards

What does LIDAR technology use to create a spatial map of a robot's environment?

Answer: Pulsed laser beams measured by return time to calculate distances

LIDAR emits rapid laser pulses and measures the time-of-flight of each returning pulse to build a precise 2D or 3D point cloud representation of the surrounding environment.

In a robotic system, what is the role of a resolver compared to an encoder for joint feedback?

Answer: A resolver is an analog magnetic device that provides position feedback immune to shock and vibration without electronic components inside

Resolvers are ruggedized analog electromagnetic transducers with no internal electronics, making them highly resistant to shock, vibration, and extreme temperatures where encoders may fail.

What potential problem does electromagnetic interference (EMI) cause in robotic sensor signal wiring, and how is it mitigated?

Answer: EMI induces noise that corrupts signal integrity; shielded, twisted-pair cables with proper grounding mitigate this

Electromagnetic interference couples noise into signal conductors; shielded twisted-pair cables cancel common-mode interference, and proper single-point grounding prevents ground loops.

Which sensor type measures the actual torque output of a robot joint rather than inferring it from motor current?

Answer: Joint-mounted strain gauge torque sensor

Strain gauge torque sensors measure the mechanical deformation of the joint structure directly, providing accurate torque feedback independent of friction, backlash, and electrical motor model assumptions.

What is the function of a safety laser scanner in a collaborative robot work cell?

Answer: It creates configurable 2D safety zones and triggers a safe stop if a person enters the protected area

Safety laser scanners continuously scan a configurable 2D field; when a person or object violates a warning or protective zone, they output a safety-rated stop signal to halt or slow the robot.

In a robotic I/O system, why are I/O signals often transmitted over a fieldbus such as EtherNet/IP or PROFINET instead of hard-wired discrete connections?

Answer: Fieldbus communication reduces wiring complexity, enables remote diagnostics, and allows flexible I/O point expansion

Industrial fieldbuses carry many I/O signals over a single network cable, dramatically reducing wiring, providing real-time diagnostics, and allowing the I/O configuration to be changed in software.

What is the purpose of performing a 'hand-eye calibration' in a robot vision system?

Answer: It establishes the spatial relationship between the camera's coordinate frame and the robot's tool or base frame

Hand-eye calibration determines the rigid transformation between the camera frame and the robot frame so that object positions detected in the image can be accurately commanded as robot target poses.