BHUVAN K K
2026HT30085
ASSIGNMENT 1
1. Task A1: Sensor Selection Table For each sensing task, select the most suitable sensor
from S1–S10 and justify your choice.
Task
Part presence detection on
conveyor
Selected Sensor ID
S3 (Through beam
photoelectric)
Metallic vs non-metallic
identification
S1 (Inductive proximity
sensor)
Height measurement of part
S6 (Laser displacement
sensor)
Detection of transparent
plastic part
S2 or S5 (Capacitive /
Ultrasonic)
Surface defect / printed
mark inspection
S7 (Industrial vision
camera)
Confirmation of part in
sorting bin
S4 (Retro reflective
photoelectric)
Justification
Provides rapid response (0.5
ms) and reliable digital
presence detection over a
wide range (0-2 m) across
the conveyor without
physical contact.
Specifically targets metallic
objects only (0-8 mm range)
with a fast 1 ms response
time, making it ideal for
distinguishing metallic parts
from non-metallic ones
Delivers high precision
(±0.05 mm accuracy over
20-120 mm) required for
accurate dimensional height
inspection of manufactured
parts.
Capacitive sensor (S2)
detects non-metallic and
transparent plastics via
dielectric constant changes;
Ultrasonic (S5) handles
solid, liquid, and transparent
objects reliably.
Offers field-of-view
dependent imaging
capability specifically
designed for shape,
orientation, surface defects,
and printed mark inspection.
Reliably detects opaque and
semitransparent objects
entering the bin using a
reflector setup with a 1 ms
response time and medium
range.
Task A2: Trade-Off Discussion:
a) Why may a capacitive sensor detect plastic parts but an inductive sensor cannot?
A capacitive sensor can detect plastic because it senses changes in capacitance/dielectric
constant, while an inductive sensor detects only metallic objects through electromagnetic
fields.
b) Why is a laser displacement sensor better than an ultrasonic sensor for precise height
measurement?
A laser displacement sensor provides higher accuracy and resolution for precise height
measurement, while ultrasonic sensors are generally less precise due to sound-wave
limitations.
c) Why might a vision camera fail even if the correct camera is selected? Mention at
least two practical reasons.
A vision camera may fail due to poor lighting and incorrect camera focus/alignment.
Other reasons include dirty lenses, reflections, or improper image-processing settings.
d) For bin confirmation, compare a photoelectric sensor and a limit switch. Which one is
better for high-speed non-contact operation?
Photoelectric sensor is better because it provides fast, non-contact detection, whereas a
limit switch requires physical contact with the bin.