Device for realizing hand-leaving detection of steering wheel by using heating material

Abstract

The utility model discloses a device for realizing hand-leaving detection of a steering wheel by using a heating material, which comprises a steering wheel framework, a heating material and a heating material, the foam layer wraps the outer side of the steering wheel framework; the heating layer covers the outer side of the foam layer; the leather layer is arranged on the outer side of the heating layer and serves as the surface of the steering wheel; the multifunctional steering wheel switch module is arranged on the steering wheel; wherein the heating layer is connected with the multifunctional steering wheel switch module, and heating control and hand separation detection are achieved. The device for realizing hand-leaving detection of the steering wheel by using the heating material provided by the utility model is simple in structure, can realize a hand-leaving detection function through the heating material on the steering wheel at the same time, and integrates heating control and hand-leaving detection functions on the multifunctional key module, so that the product cost is reduced, and the number of modules is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of steering wheel driver hands-off detection technology, and specifically relates to a device that uses heating materials to detect steering wheel hands-off. Background Technology

[0002] In the automotive industry, as autonomous driving systems have evolved from Level 1 to Level 4, hands-on / off (HOD) detection has become an indispensable feature. Currently, the mainstream HOD detection method is capacitive touch detection, which relies on the capacitance between a human hand and the steering wheel. With the increasing number of automotive companies and intensifying market competition, companies are facing increasingly stringent cost control requirements. Reducing the number of parts and streamlining manufacturing complexity while maintaining core functionality can effectively lower production costs.

[0003] Current mainstream steering wheel hands-off detection systems typically use a separate detection material, usually consisting of a layer of metal mesh, a layer of metal wire, or two layers of metal mesh bonded to the outside of the steering wheel's heating material. The detection module itself is a separate hands-off detection module. This separation of the hands-off detection module, heating control module, and multi-function button module results in low overall system integration, increasing manufacturing complexity and keeping costs high. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing hands-off detection technology, such as high cost and low integration, and to provide a device that uses heating materials to detect when a steering wheel is off-hand.

[0005] The technical solution provided by this utility model is as follows:

[0006] A device for detecting when a steering wheel is removed from hands using a heating material, comprising:

[0007] Steering wheel frame, which is the main supporting structure of the steering wheel;

[0008] A foam layer that wraps around the outside of the steering wheel frame;

[0009] A heating layer that covers the outside of the foam layer;

[0010] A leather layer is disposed on the outside of the heating layer, serving as the surface of the steering wheel;

[0011] A multi-function steering wheel switch module is mounted on the steering wheel;

[0012] The heating layer is connected to the multi-functional steering wheel switch module to achieve heating control and hands-off detection.

[0013] Preferably, the heating material of the heating layer is a linear resistance wire or a sheet resistance sheet.

[0014] Preferably, the multi-functional steering wheel switch module includes a single MCU that integrates a capacitance detection unit and a heating control unit, and has multiple programmable I / O interfaces.

[0015] Preferably, the multi-function steering wheel switch module further includes a MOS transistor, one end of which is connected to the heating layer and the other end of which is connected to the heating power supply, wherein the MOS transistor control circuit is integrated inside the multi-function steering wheel switch module.

[0016] Preferably, the multi-functional steering wheel switch module includes a capacitance detection circuit; the capacitance detection circuit is connected to the heating layer via a wiring harness and is used to detect capacitance changes between the heating layer and the steering wheel frame.

[0017] Preferably, the multi-function steering wheel switch module is equipped with a signal protection circuit to ensure signal integrity.

[0018] The beneficial effects of this utility model are: the device for detecting steering wheel hands off using heating materials provided by this utility model has a simple structure, can realize the hands-off detection function at the same time through the heating material on the steering wheel, and integrates heating control and hands-off detection functions into a multi-function button module, thereby reducing product costs and simplifying the number of modules. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the steering wheel rim described in this utility model.

[0020] Figure 2 This is a wiring diagram of the multi-functional steering wheel switch module and the heating layer described in this utility model.

[0021] Figure 3 This is a block diagram of the multi-functional steering wheel switch module system described in this utility model.

[0022] Figure 4 This is a schematic diagram of the internal heating circuit and signal protection circuit of the multi-functional steering wheel switch module described in this utility model.

[0023] Figure 5 This is a schematic diagram of the internal heating circuit, capacitor detection circuit, and signal protection circuit of the multi-functional steering wheel switch module described in this utility model.

[0024] Figure 6 This is a schematic diagram of the state of the MOS transistor when heating is turned off according to this utility model.

[0025] Figure 7This is a schematic diagram of the state of the MOS transistor when heating is turned on according to this utility model. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0027] like Figure 1-3 As shown, this utility model provides a device for detecting steering wheel removal using heating materials. The device includes a steering wheel frame, which serves as the main support structure for the steering wheel; the steering wheel frame is ring-shaped and integrally molded from high-strength zinc alloy, aluminum alloy, or magnesium alloy; a foam layer, which wraps around the outside of the steering wheel frame; the foam layer has uniform thickness and is made of low-density, highly elastic polyurethane foam material with good insulation properties, and is firmly bonded to the steering wheel frame through a hot-pressing process; a heating layer, which covers the outside of the foam layer; the heating material of the heating layer is a linear resistance wire or a sheet resistance sheet with uniform thickness; the linear resistance wire or the sheet resistance sheet is made of copper-aluminum alloy or graphene. The materials have an anti-oxidation treatment on the surface, and the conductive materials are electrically connected by welding to form a continuous conductive path. A leather layer, located outside the heating layer, serves as the steering wheel surface. This leather layer is made of top-grain cowhide, treated for waterproofing and wear resistance, and tightly adhered to the outer surface of the heating layer with a special adhesive, providing a comfortable grip for the user. A multi-function steering wheel switch module is located on the steering wheel. This module includes a heating circuit and a capacitance detection circuit for heating control and hands-off detection. The heating layer is connected to the multi-function steering wheel switch module, and the heating material in the heating layer simultaneously achieves heating control and hands-off detection.

[0028] The multi-functional steering wheel switch module includes a high-performance single MCU, which integrates a capacitance detection unit and a heating control unit. The capacitance detection unit can detect when the hand is off, and the heating control unit supports controlling external circuits to achieve the heating function. The single MCU has multiple programmable I / O interfaces, which can be flexibly configured to achieve various functions and meet the requirements of multi-functional integration. While fulfilling the functions of the switch itself, such as buttons, touch buttons, sliders, touchpads, and scroll wheels, it also supports steering wheel heating control, realizes off-hand detection and hand gesture recognition, and can recognize gloved hand grips by optimizing the capacitance detection algorithm. On the software side, the off-hand detection adopts a unique algorithm, which can detect on-hand and off-hand information in a very short time, and applies a self-learning mechanism for ambient temperature, so the detection accuracy is not affected by large temperature changes.

[0029] The multi-function steering wheel switch module connects the heating layer to the heating power supply via a MOSFET. The MOSFET is a low-on-resistance, high-switching-speed P-channel enhancement-type or N-channel enhancement-type MOSFET, and the MOSFET control circuit is integrated inside the multi-function steering wheel switch module. The heating layer is connected to the capacitance detection circuit inside the multi-function steering wheel switch module via a wiring harness. The multi-function steering wheel switch module also has an independent signal protection circuit to ensure the integrity and stability of the detection signal, so that the hands-off detection function is not affected by the heating function.

[0030] like Figure 4-5 As shown, the heating power supply is connected to the source S of the first MOSFET, the drain D of the first MOSFET is connected to the source S of the second MOSFET, the drain D of the second MOSFET is connected to the positive terminal of the heating material of the heating layer, the negative terminal of the heating material of the heating layer is connected to the drain D of the third MOSFET, and the source S of the third MOSFET is connected to the negative terminal of the heating power supply, i.e., the source S of the third MOSFET is grounded, thus forming a heating circuit for heating the heating layer, specifically for heating the steering wheel. The gate G of the first MOSFET is connected to resistor R1 and a switch, forming a control circuit for the first MOSFET. The drain D of the second MOSFET is connected to resistor R3 and a switch, forming a signal protection circuit. The gate G of the third MOSFET is connected to resistor R4, forming a control circuit for the third MOSFET. The single MCU controls the first and third MOSFET control circuits, connecting the positive and negative terminals of the heating power supply to the first and third MOSFETs, thus connecting the heating circuit and turning the steering wheel heating on. Conversely, the single MCU controls the first and third MOSFET control circuits, disconnecting the positive and negative terminals of the heating power supply from the first and third MOSFETs, thus disconnecting the heating circuit and turning the steering wheel heating off. The negative terminal of the heating material in the heating layer is simultaneously connected to resistors R5 and R6 and capacitor C1, forming a capacitance detection circuit for hands-free detection. A switching transistor is connected to the capacitance detection circuit to ensure the integrity and stability of the detection signal, preventing the hands-free detection function from being affected by the heating function.

[0031] like Figure 6 As shown, when the steering wheel heating is in the off state, the MOS transistor is in the off state, the connection state between the heating layer and the capacitance detection circuit changes, and the heating layer is used entirely for off-hand detection, so that the capacitance detection circuit can focus on detecting the capacitance change between the heating material of the heating layer and the steering wheel frame, thereby determining whether the driver is holding the steering wheel and constantly monitoring the contact between the driver's hands and the steering wheel.

[0032] like Figure 7As shown, when the steering wheel heating is on, the MOSFET is on, the heating layer is connected to the heating power supply, and the heating material of the heating layer begins to enter the heating mode. In this mode, to balance the heating effect and the timeliness of the hands-off detection function, the single MCU will control the on / off state of the MOSFET in a time-division manner. When the heating mode is on, the single MCU controls the MOSFET to turn on in a time-division manner according to a specific time pattern to reasonably balance the time required for heating and detection. The multi-functional steering wheel switch module adopts a time-division multiplexing mechanism to coordinate the heating and hands-off detection functions. In each working cycle, about 90% of the time is allocated to the heating mode to ensure that the steering wheel can heat up quickly and effectively, providing the driver with a comfortable grip experience; about 10% of the time is used for hands-off detection. During this period, the single MCU quickly switches the circuit state to temporarily stop the steering wheel heating and switch to capacitance detection to obtain the driver's hand status information as densely as possible. Even during the heating process, it can detect whether the driver has taken their hands off the wheel in a timely and accurate manner to ensure driving safety.

[0033] This utility model provides a device for detecting steering wheel hands-off using heating materials. It features a simple structure, eliminating the need for additional hands-off detection materials by using the heating material as the detection material itself. Furthermore, it integrates hands-off detection and heating control functions into a multi-function button module controlled by a single MCU, effectively reducing the number of independent modules and significantly lowering wiring and assembly costs, thus alleviating cost pressures on automakers. The integrated design of the multi-function button module optimizes the system architecture, reducing the complexity of connections and communication between modules. The time-sharing control of the single MCU improves system response speed and stability, reduces the number of components and module connections, lowers the probability of failure, reduces after-sales maintenance costs and time, and greatly enhances the user experience. The time-sharing multiplexing of the heating layer for heating and hands-off detection, combined with the time-sharing control of the MOSFET by the single MCU, rationally allocates heating and detection time. While ensuring heating efficiency, it performs hands-off detection as densely as possible, achieving efficient utilization of hardware resources, avoiding resource waste, and comprehensively improving system performance and operating efficiency.

[0034] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A device for detecting when a steering wheel is removed from the hands using a heating material, characterized in that, include: Steering wheel frame, which is the main supporting structure of the steering wheel; A foam layer that wraps around the outside of the steering wheel frame; A heating layer that covers the outside of the foam layer; A leather layer is disposed on the outside of the heating layer, serving as the surface of the steering wheel; A multi-function steering wheel switch module is mounted on the steering wheel; The heating layer is connected to the multi-functional steering wheel switch module to achieve heating control and hands-off detection.

2. The device for detecting steering wheel removal using heating material according to claim 1, characterized in that, The heating material of the heating layer is a linear resistance wire or a sheet resistance sheet.

3. The device for detecting steering wheel removal using heating material according to claim 1, characterized in that, The multi-functional steering wheel switch module includes a single MCU, which integrates a capacitance detection unit and a heating control unit, and has multiple programmable I / O interfaces.

4. The device for detecting steering wheel removal using heating material according to claim 3, characterized in that, The multi-function steering wheel switch module also includes a MOS transistor, one end of which is connected to the heating layer and the other end of which is connected to the heating power supply. The control circuit of the MOS transistor is integrated inside the multi-function steering wheel switch module.

5. The device for detecting steering wheel removal using heating material according to claim 1, characterized in that, The multi-functional steering wheel switch module is equipped with a capacitance detection circuit; the capacitance detection circuit is connected to the heating layer via a wiring harness and is used to detect the capacitance change between the heating layer and the steering wheel frame.

6. The device for detecting steering wheel removal using heating material according to claim 5, characterized in that, The multi-function steering wheel switch module is equipped with a signal protection circuit to ensure signal integrity.

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