Page 117 - Toucpad robotics C11

The sensor precisely measures the time of flight for each laser pulse – the time it takes for the light to travel from the
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sensor, reflect off an object, and return to the receiver.
Since the speed of light is constant and extremely fast, the distance to the object can be calculated with very high accuracy:
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Distance = (Speed of Light × Time of Flight) / 2
By rotating the laser emitter and receiver, or by using mirrors, the LIDAR system can collect thousands or millions
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of distance measurements across a wide field of view. These individual distance points, when combined, create a
detailed 3D representation of the environment, known as a Point Cloud.

Applications in Robotics
High-Resolution 3D Mapping: Creating incredibly detailed and accurate 3D maps of indoor and outdoor environments,
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crucial for autonomous navigation.

u Simultaneous Localisation and Mapping (SLAM): Used by autonomous vehicles and robots to simultaneously build
a map of an unknown environment and determine their own precise location within that map.
Obstacle Detection and Tracking: Identifying even small obstacles at long ranges and tracking their movement for
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collision avoidance.
Navigation for Autonomous Vehicles: The primary perception sensor for many self-driving cars, enabling them to
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“see” their surroundings with extreme precision.
Industrial Automation: Mapping factory floors for automated guided vehicles or inspecting large structures.
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Advantages
Extremely High Accuracy: Provides highly precise distance measurements.
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High Resolution 3D Data: Generates rich 3D point clouds, offering a detailed understanding of the environment’s
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geometry.
Effective in Various Lighting Conditions: Works well in both bright light and complete darkness (as it uses its own
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light source).
Long Range: Can detect objects at much greater distances than infrared or ultrasonic sensors (hundreds of meters
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for some types).

u Not Affected by Colour/Texture (as much): Less influenced by the surface properties of objects compared to
vision cameras.

Disadvantages
High Cost: Significantly more expensive than other sensor types, especially high-resolution models.
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u Performance Degrades in Adverse Weather: Rain, fog, or heavy snow can scatter laser light, significantly degrading
performance.
Bulkier and Heavier: Compared to other sensors, LIDAR units can be physically larger and heavier.
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Data Processing Intensive: Generates enormous amounts of data (point clouds) that require powerful computing
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resources and sophisticated algorithms for processing and interpretation.

Touch Sensors (Tactile Sensors)

Description
A Touch sensor, also known as a tactile sensor, is a device that detects physical contact
or pressure. They are designed to mimic a robot’s sense of touch, allowing it to feel its
interaction with objects or surfaces. They can range from simple switches to complex
arrays that can detect force distribution.

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Electrical and Control Systems