Capacitive Robot Proximity Sensing With Shielded False Detection Control
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Solution Overview
Problem
Conventional proximity sensors on robots often mistakenly detect other parts of the robot as obstacles, leading to inaccurate obstacle detection and potential unnecessary stopping of the robot.
Innovation Solution
A capacitive proximity detection system that includes a shield signal output unit to prevent the proximity sensor from detecting other parts of the robot, using a shield electrode and a robot arm shield circuit to apply a shield signal that reduces capacitance changes, thereby preventing false obstacle detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacitive proximity sensor is mounted on a robot to detect obstacles, then the robot can detect proximity to objects, but the sensor may mistakenly detect other parts of the robot as obstacles
Solution Approach 1:
A shield electrode is introduced as an intermediary element between the proximity sensor and other robot parts. The shield electrode is driven by a shield signal generator to create an electric field that cancels out the capacitive coupling between the sensor and other robot components, thereby preventing false obstacle detections while maintaining reliable obstacle detection capability
Solution Approach 2:
The system changes the electrical parameters (voltage, frequency) of the shield electrode dynamically to match the operating conditions of the proximity sensor. By adjusting the shield signal parameters, the system optimizes the cancellation effect against capacitive interference from different robot parts during various motion states, resolving the contradiction between detection sensitivity and false alarm rate
2Adaptability or versatility
If the robot uses capacitive sensing to detect proximity, then it can sense objects near the robot, but it cannot distinguish between external objects and internal robot parts
Solution Approach 1:
The robot body is segmented into distinct electrical zones: the sensor mounting position, other robot parts, and the shield electrode. Each segment has controlled electrical characteristics that allow the sensor to differentiate between external objects and internal components based on their unique capacitive signatures and spatial relationships
Solution Approach 2:
The shield electrode acts as an intermediary that creates a controlled electric field boundary. This boundary helps the sensor distinguish between targets inside the robot (blocked or shielded by the electrode) and external objects (beyond the shield boundary), thereby improving target identification accuracy while maintaining broad detection range
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enhances the accuracy of obstacle detection by preventing the robot's own parts from being mistakenly detected as obstacles, ensuring more precise control of the robot's movements.
Implementation Method 1
a proximity sensor that is a capacitive sensor mounted on a mounting position on a robot, the proximity sensor being configured to detect proximity between the mounting position and an object
Implementation Method 2
a shield signal output unit configured to apply a shield signal for preventing the proximity sensor from detecting proximity of another position of the robot other than the mounting position
Data Source
AI summary
A proximity detection system includes a proximity sensor that is a capacitive sensor mounted on a mounting position on a robot, the proximity sensor being configured to detect proximity between the mounting position and an object; and a shield signal output unit configured to apply a shield signal for preventing the proximity sensor from detecting proximity of another position of the robot other than the mounting position.