Wireless Displacement Measuring Apparatus for Vehicle Seats
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Solution Overview
Problem
Existing displacement measuring systems for seat devices and vehicle seats require complex wiring due to the large number of pressure-sensitive cells and sensors, leading to increased complexity and potential measurement inaccuracies.
Innovation Solution
A displacement measuring apparatus using a plurality of reflective members embedded in a flexible sheet, transmitting and receiving radio waves to calculate displacement without the need for cables, utilizing millimeter waves and electrically conductive or magnetic materials to enhance reflection and reduce measurement interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If pressure-sensitive cells and pressure sensors are arranged to cover the entire seat to measure pressurization, then the measurement coverage and detection range are improved, but the wiring complexity increases significantly
Solution Approach 1:
The patent replaces the mechanical wiring system with an electromagnetic field-based measurement system. Instead of using cables to extract signals from each pressure sensor, the invention uses radar waves to non-contactly measure the displacement of the seating surface. The radar transmission unit sends electromagnetic waves through the seat, and the receiving unit detects the reflected waves to calculate displacement, completely eliminating the need for physical wiring to each measurement point.
Solution Approach 2:
The patent makes the radar system perform multiple functions: it measures displacement at multiple points simultaneously, determines load distribution, and provides comprehensive seating surface information all through a single wireless radar apparatus, replacing what would otherwise require multiple separate wired sensors and their associated wiring infrastructure.
2Quantity of substance
If the number of pressure-sensitive cells or pressure sensors is increased to detect a wide range of loads, then the detection capability is improved, but the number of wires and wiring complexity increases
Solution Approach 1:
The patent replaces the mechanical wiring system with an electromagnetic field-based measurement system. Instead of using cables to extract signals from each pressure sensor, the invention uses radar waves to non-contactly measure the displacement of the seating surface. The radar transmission unit sends electromagnetic waves through the seat, and the receiving unit detects the reflected waves to calculate displacement, completely eliminating the need for physical wiring to each measurement point.
3Ease of operation
If cables are used to extract output signals from pressure sensors, then signal extraction is achieved, but measurement accuracy deteriorates due to wiring complications
Solution Approach 1:
The patent replaces the mechanical wiring system with an electromagnetic field-based measurement system. Instead of using cables to extract signals from each pressure sensor, the invention uses radar waves to non-contactly measure the displacement of the seating surface. The radar transmission unit sends electromagnetic waves through the seat, and the receiving unit detects the reflected waves to calculate displacement, completely eliminating the need for physical wiring to each measurement point.
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
Enables accurate displacement measurement of multiple portions without cumbersome wiring, maintaining measurement quality by ensuring independent displacement calculation of each reflective member, thus simplifying the measurement process and improving accuracy.
Implementation Method 1
a transmission unit configured to transmit a radio wave of a predetermined frequency that can pass through a human body to each of the plurality of reflective members, a receiving unit configured to receive the radio wave of the predetermined frequency reflected by each of the plurality of reflective members and returned
Implementation Method 2
The radio wave of the predetermined frequency is preferably a millimeter wave. The radio wave of the predetermined frequency is preferably a radio wave in a 27-GHz band or a 60-GHz band. This allows measurement of displacement, with a person seated on the detection target.
Data Source
Figure 1~2B
Figure 3~4
AI summary
A displacement measuring apparatus includes a plurality of reflective members disposed at a detection target, a signal source and a transmitting antenna that transmit a radio wave of a predetermined frequency that can pass through a human body to each of the plurality of reflective members, a receiving antenna and a mixer that receive the radio wave reflected by each of the plurality of reflective members and returned, a distance calculation unit that calculates information on distances to the plurality of reflective members based on information on a time until the transmitted radio wave returns, and a displacement-distribution measuring unit that calculates a displacement of each of the plurality of reflective members based on the information on the distances.