Vehicle Sensor Retracted by Shape-Memory Alloy
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Solution Overview
Problem
Existing sensor arrangements on vehicle bumpers are prone to damage during low-speed collisions, leading to high repair costs and potential legal issues due to their exposed position.
Innovation Solution
A sensor arrangement featuring a shape-memory alloy traction means and a restoring spring system that moves the sensor from an active position to a protected position within the vehicle interior during impending or detected low-speed collisions, preventing damage and ensuring the sensor can return to its functional position post-collision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sensor is installed in an opening of the outer paneling with the active sensor surface flush with the outer paneling, then the sensor function is optimized, but the sensor is vulnerable to damage during low-speed collisions
Solution Approach 1:
The sensor is made movable between a retracted position (inside the bumper) and an extended position (flush with outer paneling) through a guide mechanism. This dynamic positioning allows the sensor to be protected during collisions while maintaining optimal function during normal operation.
Solution Approach 2:
The sensor is preemptively retracted into the protected position before a collision occurs, as detected by collision detection sensors. This preliminary action prevents damage before it can occur, allowing the sensor to resume function quickly after the event.
2Productivity
If the sensor is positioned to be flush with the outer paneling, then the sensor can perform its operational function effectively, but high repair costs are incurred due to damage during parking bumps
Solution Approach 1:
The guide mechanism provides a protective cushioning structure that absorbs collision forces before they reach the sensor. The sensor remains retracted within the bumper housing during low-speed events, preventing damage and reducing repair costs while maintaining full operational capability when needed.
3Object-affected harmful factors
If the sensor is installed in a protected position inside the bumper, then the sensor is protected from collision damage, but the sensor function is compromised
Solution Approach 1:
The sensor transitions between retracted and extended positions based on operational needs and collision detection. During normal operation, the sensor extends to the flush position for optimal function; upon detecting an impending collision, it retracts to the protected position, thus achieving both protection and functionality at different times.
4Object-affected harmful factors
If a movable sensor arrangement with guide mechanism is implemented, then the sensor is protected during low-speed collisions, but the device complexity increases
Solution Approach 1:
A guide mechanism acts as an intermediary between the sensor and the collision force. This intermediate structure provides a simple yet effective protection system that allows sensor movement without requiring complex active control systems, reducing overall device complexity while maintaining protection capability.
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 solution effectively protects sensors from low-speed collisions by relocating them to a safe position, preventing damage and ensuring the sensor's operational functionality is maintained, with the restoring spring mechanism returning the sensor to its active position post-event.
Implementation Method 1
the traction means is designed as a traction spring made of a shape-memory alloy; In an imminent or a currently detected weak collision, i.e. in the low-speed range of less than 4 km/h, the traction means consisting of a shape-memory alloy is thermally activated, whereby the traction means is shortened
Implementation Method 2
the restoring means is designed as a conventional traction spring; The sensor is moved by means of the restoring means from the protected position back to its active position
Data Source
AI summary
An arrangement for a sensor having a sensor-active surface on or behind an exterior attachment part of a vehicle includes a sensor guide. The sensor guide includes a traction element made of a shape-memory alloy and a restoring element. The traction element moves the sensor in the direction of the vehicle interior between an active position and a protected position in response to a detected impending collision in the low-speed range or a detected collision in the low-speed range. The restoring element moves the sensor back to the active position from the protected position.