Steering wheel hands-off detection device, steering wheel and vehicle

Abstract

The application relates to the field of automobile technology and discloses a steering wheel hand-off detection device, a steering wheel and a vehicle, which solve the problem that existing steering wheel hand-off detection cannot determine whether hand-off is single-handed or double-handed and which hand is off. The steering wheel hand-off detection device is provided with a first and a second conductor arranged in the interior of a steering wheel framework, a third and a fourth conductor arranged in the exterior of the steering wheel framework and a control unit; the opposite parts of the first conductor and the third conductor form a first capacitor, the opposite parts of the second conductor and the fourth conductor form a second capacitor, and the control unit judges which hand of a user is in a hand-off state or both hands are in a hand-off state according to the capacitance changes of the first and second capacitors.

Description

Technical Field

[0001] This application relates to the field of automotive technology, and in particular to a steering wheel hands-off detection device. Background Technology

[0002] As people's living standards improve, more and more families are owning cars. The steering wheel, as a crucial component of the car's steering system, is not only for steering but also serves multiple functions, such as ECG (electrocardiogram) detection and hands-off detection. ECG detection measures the driver's ECG signal. Hands-off detection monitors whether the driver's hands are on the steering wheel for safe driving purposes.

[0003] In newer cars, the steering wheel ECG sampling system requires a metal trim strip to measure the driver's ECG signal. Traditional ECG chips include hands-off detection, but the metal trim strip interferes with this function. When hands leave the steering wheel, it cannot determine whether both hands or one hand are off, or which hand is off, thus preventing the system from triggering an alarm during hands-off detection. Summary of the Invention

[0004] The purpose of this application is to provide a steering wheel off-hand detection device, a steering wheel, and a vehicle, which can solve the problem that existing steering wheel off-hand detection methods cannot determine whether it is a single hand or two hands off the steering wheel, or which hand is off the steering wheel.

[0005] This application discloses a steering wheel hands-off detection device, comprising:

[0006] The first and second conductors are installed inside the steering wheel frame;

[0007] The third and fourth conductors are disposed on the outside of the steering wheel frame, and the opposite portions of the first conductor and the third conductor form a first capacitor, and the opposite portions of the second conductor and the fourth conductor form a second capacitor;

[0008] The control unit is used to determine which of the user's hands is off-hand or both hands are off-hand simultaneously based on the capacitance changes of the first and second capacitors.

[0009] In a preferred embodiment, the first and second conductors are insulated from the third and fourth conductors;

[0010] The relative portions of the first conductor and the third conductor are arranged in parallel, and the relative portions of the second conductor and the fourth conductor are arranged in parallel.

[0011] In a preferred embodiment, the first and second conductors are connected end to end, arranged around the steering wheel frame, and wrapped with an insulating layer.

[0012] In a preferred embodiment, the control unit includes first and second charging and discharging circuits and a control circuit, wherein the first and second charging and discharging circuits are electrically connected to the first and second conductors, respectively, and the control circuit is electrically connected to the first and second charging and discharging circuits, respectively.

[0013] When the first and second charging and discharging circuits are activated, they charge and discharge the first capacitor and the second capacitor respectively and detect the charging and discharging time to generate the first and second output frequencies. The control circuit determines which of the user's hands is off-hand or both hands are off-hand at the same time based on the changes in the first and second output frequencies.

[0014] In a preferred embodiment, the first and second charging and discharging circuits are respectively first and second pulse generating circuits, or the first and second charging and discharging circuits are respectively first and second resonant circuits.

[0015] In a preferred embodiment, the control circuit stores an initial frequency, and the control circuit is further configured to compare the first and second output frequencies with the initial frequency respectively, and when the first and second output frequencies change relative to the initial frequency, determine which hand of the user is in a hands-free state or both hands are in a hands-free state simultaneously.

[0016] In a preferred embodiment, the steering wheel off-hand detection device further includes an ECG detection module, the two detection terminals of which are electrically connected to the third and fourth conductors respectively, and the output terminal of the ECG detection module is connected to the control circuit.

[0017] The ECG detection module detects the user's hand position by using the third and fourth conductors. When the user's hand position is detected, the control circuit is activated to start the first and second charging and discharging circuits for charging.

[0018] In a preferred embodiment, the ECG detection module includes a resistor connected in series in the ECG detection circuit, and the user is determined to have removed their hand when the detection circuit of the ECG detection module is broken.

[0019] This application also discloses a steering wheel, the steering wheel including first and second metal trim strips disposed on the left and right sides and the ECG detection module, the metal trim strips being electrically connected to two detection terminals of the ECG detection module respectively; and the steering wheel further includes:

[0020] First and second conductors are disposed inside the steering wheel frame, the first conductor and the opposite portion of the first metal trim strip form a first capacitor, and the second conductor and the opposite portion of the second metal trim strip form a second capacitor;

[0021] The control unit, which is electrically connected to the output of the ECG detection module, is used to determine which of the user's hands is off-hand or both hands are off-hand simultaneously based on the capacitance changes of the first and second capacitors.

[0022] This application also discloses a vehicle including the steering wheel hands-off detection device or steering wheel described above.

[0023] The advantages and beneficial effects of this invention include at least the following:

[0024] (1) The state of the left and right hands being released is determined by detecting the change in capacitance of the capacitor formed by the two conductors on the left and right sides and the two conductors inside, thus realizing the separate detection of the left and right hands.

[0025] (2) Without changing the existing steering wheel ECG sampling system, adding a conductor inside the steering wheel frame can make the original two metal trim strips and the internal conductor form two capacitors. By detecting the change in the capacitance of the two capacitors, the left and right hand release status can be determined separately, realizing the separate detection of the left and right hands. It is highly operable and easy to implement.

[0026] The specification of this application contains numerous technical features distributed across various technical solutions. Listing all possible combinations of these technical features (i.e., technical solutions) would make the specification excessively lengthy. To avoid this problem, the various technical features disclosed in the above-described invention, the various technical features disclosed in the following embodiments and examples, and the various technical features disclosed in the accompanying drawings can be freely combined to form various new technical solutions (all of which are considered to have been described in this specification), unless such a combination of technical features is technically infeasible. For example, one example discloses feature A+B+C, and another example discloses feature A+B+D+E. Features C and D are equivalent technical means that serve the same function, and technically only one needs to be used; they cannot be used simultaneously. Feature E can technically be combined with feature C. Therefore, the solution A+B+C+D should not be considered as described because it is technically infeasible, while the solution A+B+C+E should be considered as described. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the steering wheel structure based on this application.

[0028] Figure 2This is a schematic diagram of a steering wheel hands-off detection device according to an embodiment of this application.

[0029] Figure 3 This is a schematic diagram of a steering wheel off-hand detection circuit according to an embodiment of this application. Detailed Implementation

[0030] In the following description, many technical details are presented to help the reader better understand this application. However, those skilled in the art will understand that the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0031] This application addresses how to identify whether a person's hands have left the steering wheel (one hand or both hands), and which hand has left. To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0032] The first embodiment of this application relates to a steering wheel hands-off detection device. The device includes first and second conductors disposed inside the steering wheel frame, third and fourth conductors disposed outside the steering wheel frame, and a control unit. The opposite portions of the first and third conductors form a first capacitor, and the opposite portions of the second and fourth conductors form a second capacitor. The control unit determines which hand of the user is off-hand or both hands are off-hand simultaneously based on the capacitance changes of the first and second capacitors.

[0033] Optionally, the first and second conductors are insulated from the third and fourth conductors.

[0034] Optionally, the relative portions of the first conductor and the third conductor are arranged in parallel, and the relative portions of the second conductor and the fourth conductor are arranged in parallel.

[0035] The specific arrangement of the first and second conductors can vary. Optionally, the first and second conductors can be an integral arrangement connected end to end, surrounding the steering wheel frame and wrapped with an insulating layer. Optionally, the first and second conductors can be conductor strips of a predetermined length respectively arranged on the left and right sides of the steering wheel, with part or all of the conductor strips parallel to and opposite the third and fourth conductors to form corresponding capacitors.

[0036] Optionally, the control unit includes first and second charging and discharging circuits and a control circuit, wherein the first and second charging and discharging circuits are electrically connected to the first and second conductors respectively, and the control circuit is electrically connected to the first and second charging and discharging circuits respectively; when the first and second charging and discharging circuits are activated, they charge and discharge the first capacitor and the second capacitor respectively and detect the charging and discharging time to generate first and second output frequencies, and the control circuit determines which hand of the user is off-hand or both hands are off-hand at the same time based on the changes in the first and second output frequencies.

[0037] The first and second charging and discharging circuits can take many forms. Optionally, the first and second charging and discharging circuits can be first and second pulse generating circuits, which detect and generate first and second oscillation frequencies based on the charging and discharging time of the first and second capacitors. Optionally, the first and second charging and discharging circuits can be first and second resonant circuits, which detect and generate first and second resonant frequencies based on the charging and discharging time of the first and second capacitors.

[0038] Optionally, the control circuit stores an initial frequency in advance. The control circuit is also used to compare the first and second output frequencies with the initial frequency respectively. When the first and second output frequencies change relative to the initial frequency, it determines which hand of the user is in the off-hand state or both hands are in the off-hand state at the same time.

[0039] Optionally, the steering wheel off-hand detection device further includes an ECG detection module. The two detection terminals of the ECG detection module are electrically connected to the third and fourth conductors, respectively, and the output terminal of the ECG detection module is connected to the control circuit. The ECG detection module detects the user's off-hand state through the third and fourth conductors. When the user's off-hand state is detected, the control circuit is controlled to start the first and second charging and discharging circuits for charging.

[0040] Optionally, the ECG detection module includes a resistor connected in series in the ECG detection circuit, and the user is determined to have removed their hand when the detection circuit of the ECG detection module is broken.

[0041] In this embodiment, when the human body grips the third or fourth conductive body, the change in the area of ​​the parallel plate due to the capacitance effect leads to a change in the capacitance of the steering wheel. Based on this principle, this patent detects the change in capacitance to determine which hand is off-hand.

[0042] To better understand the technical solution of this application, a specific embodiment will be used for illustration below. The details listed in this embodiment are mainly for ease of understanding and are not intended to limit the scope of protection of this application.

[0043] refer to Figure 1As shown, a wire LL is first laid inside the steering wheel, parallel to the outer metal trim strip on the steering wheel, and insulated from it. Metal contact points LA and RA are respectively set on the left and right sides of the outer metal trim strip, forming capacitances with the internal wires. When a person grips the outer metal trim strip, the area of ​​the parallel plate changes due to the capacitance effect, causing a change in the steering wheel capacitance. This patent uses this principle to detect the capacitance change, thus determining whether the hand has left the steering wheel.

[0044] refer to Figure 2 As shown, the steering wheel hands-off detection device includes first and second pulse generating circuits connected to metal contact points LA and RA, respectively, and a control circuit (e.g., an MCU). The first and second pulse generating circuits charge and discharge the capacitor formed by the outer metal trim and the inner wire LL, respectively. The first and second pulse generating circuits detect the charging and discharging time and generate first and second oscillation frequencies. The control circuit determines whether the steering wheel is off-hand based on changes in the first and second oscillation frequencies. A change in oscillation frequency indicates that the corresponding capacitance has changed due to the hands being off, causing a change in the charging and discharging time, and thus a change in the oscillation. When the steering wheel is off-hand, the capacitance between the outer metal trim and the inner wire LL is a fixed value; therefore, the initial oscillation frequency generated by the pulse generating circuit should also be a fixed value. When the hands are gripped, the change in capacitance causes the output frequency to shift relative to the initial frequency. Therefore, the change in output frequency can be used to determine whether the steering wheel is off-hand or off-hand, and which hand is off-hand.

[0045] Furthermore, the aforementioned steering wheel hands-off detection device also includes an ECG detection module connected to the control circuit, used to detect the driver's ECG signal. The ECG detection module can detect whether the driver has taken their hands off the steering wheel while detecting the ECG signal. The ECG detection module includes a resistor; when the ECG detection module forms an open circuit, it determines that the user has taken their hands off the steering wheel.

[0046] refer to Figure 3 As shown, Figure 3 The specific circuit connection is shown. C42 and C47 represent the capacitors formed by the external metal trim and the internal wire LL, respectively. IC1 and IC2 chips represent the pulse generation circuit. FREQIN1 and FREQIN2 represent the oscillation signals output by IC1 and IC2, respectively. Based on the oscillation signals FREQIN1 and FREQIN2, the MCU can determine the change in the charging and discharging time of capacitors C42 and C47, thereby deriving the change in capacitors C42 and C47, concluding which hand was removed, and triggering an alarm.

[0047] When the ECG detection module detects that the user has removed their hand from the ECG signal, it activates LEAD EN. Two chips, IC1 and IC2, each generate pulse signals to charge and discharge capacitors C42 and C47. Based on the charging and discharging time of capacitors C42 and C47, they output frequencies FREQIN1 and FREQIN2 to the MCU for judgment. The MCU determines which of FREQIN1 and FREQIN2 is the initial fixed frequency, thus determining which hand is still in the hand, which hand is removed, or both hands are removed, thereby determining the hand-removal status and triggering an alarm.

[0048] Subsequently, after the user grips the external metal trim, capacitors C42 and C47 change. This change causes the output frequencies of chips IC1 and IC2 to shift relative to their initial fixed frequencies, thus indicating that the user has gripped the steering wheel. Once the MCU determines that both hands have left and then re-grasp the steering wheel, it disables lead-in and the ECG detection module normally acquires the ECG signal.

[0049] In addition, the pulse generation circuit of this embodiment can also be a resonant circuit, that is, the first and second pulse generation circuits are respectively a first resonant circuit and a second resonant circuit. The first resonant circuit and the second resonant circuit detect and generate a first resonant frequency and a second resonant frequency according to the charging and discharging time of the first capacitor and the second capacitor, respectively.

[0050] This solution only requires a hand to touch the metal trim strip to detect whether a hand is connected to RA or LA. By detecting changes in the capacitance of RA / LA to ground, the chip changes the charging and discharging time of the RA / LA, thus determining whether a hand has left the device and triggering an alarm.

[0051] The second embodiment of this application relates to a steering wheel, which includes a steering wheel hands-off detection device. The steering wheel hands-off detection device includes first and second conductors disposed inside the steering wheel frame, third and fourth conductors disposed outside the steering wheel frame, and a control unit.

[0052] The first conductor and the third conductor form a first capacitor, and the second conductor and the fourth conductor form a second capacitor. The control unit determines which hand of the user is off-hand or both hands are off-hand at the same time based on the capacitance changes of the first and second capacitors.

[0053] Optionally, the first and second conductors are insulated from the third and fourth conductors.

[0054] Optionally, the relative portions of the first conductor and the third conductor are arranged in parallel, and the relative portions of the second conductor and the fourth conductor are arranged in parallel.

[0055] Optionally, the first and second conductors can be an integral arrangement connected end to end, surrounding the steering wheel frame and wrapped with an insulating layer, or they can be provided with preset lengths on the left and right sides of the steering wheel, with some or all of them parallel to the third and fourth conductors to form a capacitor.

[0056] Optionally, the control unit includes first and second charging and discharging circuits and a control circuit, wherein the first and second charging and discharging circuits are electrically connected to the first and second conductors respectively, and the control circuit is electrically connected to the first and second charging and discharging circuits respectively; when the first and second charging and discharging circuits are activated, they charge and discharge the first capacitor and the second capacitor respectively and detect the charging and discharging time to generate first and second output frequencies, and the control circuit determines which hand of the user is off-hand or both hands are off-hand at the same time based on the changes in the first and second output frequencies.

[0057] The first and second charging and discharging circuits can take many forms. Optionally, the first and second charging and discharging circuits can be first and second pulse generating circuits, which detect and generate first and second oscillation frequencies based on the charging and discharging time of the first and second capacitors. Optionally, the first and second charging and discharging circuits can be first and second resonant circuits, which detect and generate first and second resonant frequencies based on the charging and discharging time of the first and second capacitors.

[0058] Optionally, the control circuit stores an initial frequency. The control circuit is also used to compare the first and second output frequencies with the initial frequency, respectively. When the first and second output frequencies change relative to the initial frequency, it determines which of the user's hands is in a hands-free state or both hands are in a hands-free state at the same time.

[0059] Optionally, the steering wheel off-hand detection device further includes an ECG detection module. The two detection terminals of the ECG detection module are electrically connected to the third and fourth conductors, respectively, and the output terminal of the ECG detection module is connected to the control circuit. The ECG detection module detects the user's off-hand state through the third and fourth conductors. When the user's off-hand state is detected, the control circuit is controlled to start the first and second charging and discharging circuits for charging.

[0060] Optionally, the ECG detection module includes a resistor connected in series in the ECG detection circuit, and the user is determined to have removed their hand when the detection circuit of the ECG detection module is broken.

[0061] It should be noted that the detection unit in this embodiment can be the detection unit in the first embodiment. Therefore, the specific details of the detection unit in the first embodiment can be used in this embodiment.

[0062] The third embodiment of this application relates to a steering wheel, which includes an ECG detection module, first and second metal trim strips disposed on the left and right sides, first and second conductors disposed inside the steering wheel frame, and a control unit.

[0063] The first metal trim strip is electrically connected to one detection terminal of the ECG detection module, and the second metal trim strip is electrically connected to the other detection terminal of the ECG detection module.

[0064] The opposing portions of the first conductor and the first metal trim strip form a first capacitor, and the opposing portions of the second conductor and the second metal trim strip form a second capacitor;

[0065] The control unit determines which of the user's hands is off-hand or both hands are off-hand simultaneously based on the changes in the capacitance of the first and second capacitors.

[0066] Optionally, the ECG detection module can be located inside or outside the steering wheel.

[0067] Optionally, the first and second conductors are insulated from the third and fourth conductors.

[0068] Optionally, the opposite portions of the first conductor and the first metal trim are arranged in parallel, and the opposite portions of the second conductor and the second metal trim are arranged in parallel.

[0069] Optionally, the first and second conductors may be integrally formed wires connected end to end, encircling the steering wheel frame and wrapped with an insulating layer.

[0070] Optionally, the control unit includes first and second charging and discharging circuits and a control circuit, wherein the first and second charging and discharging circuits are electrically connected to the first and second conductors respectively, and the control circuit is electrically connected to the first and second charging and discharging circuits respectively; when the first and second charging and discharging circuits are activated, they charge and discharge the first capacitor and the second capacitor respectively and detect the charging and discharging time to generate first and second output frequencies, and the control circuit determines which hand of the user is off-hand or both hands are off-hand at the same time based on the changes in the first and second output frequencies.

[0071] The first and second charging and discharging circuits can take many forms. Optionally, the first and second charging and discharging circuits can be first and second pulse generating circuits, which detect and generate first and second oscillation frequencies based on the charging and discharging time of the first and second capacitors. Optionally, the first and second charging and discharging circuits can be first and second resonant circuits, which detect and generate first and second resonant frequencies based on the charging and discharging time of the first and second capacitors.

[0072] Optionally, the control circuit stores an initial frequency. The control circuit is also used to compare the first and second output frequencies with the initial frequency, respectively. When the first and second output frequencies change relative to the initial frequency, it determines which of the user's hands is in a hands-free state or both hands are in a hands-free state at the same time.

[0073] Optionally, the output of the ECG detection module is connected to the control circuit; the ECG detection module detects the user's hand-off state through the third and fourth conductors, and controls the control circuit to start the first and second charging and discharging circuits for charging when the user's hand-off state is detected.

[0074] Optionally, the ECG detection module includes a resistor connected in series in the ECG detection circuit, and the user is determined to have removed their hand when the detection circuit of the ECG detection module is broken.

[0075] The fourth embodiment of this application relates to a vehicle that includes any of the steering wheel hands-off detection devices of the first embodiment, any of the steering wheels described in the second embodiment, or any of the steering wheels described in the third embodiment. Therefore, the specific details of the steering wheel hands-off detection device of the first embodiment, the steering wheel of the second embodiment, and the steering wheel of the third embodiment can all be used in this embodiment, and will not be repeated here.

[0076] It should be noted that in this patent application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this patent application, if it refers to performing an action according to an element, it means performing the action at least according to that element, including two cases: performing the action only according to that element, and performing the action according to that element and other elements. Expressions such as "multiple," "repeatedly," and "various" include two, two times, two kinds, and more than two, more than two times, and more than two kinds.

[0077] All documents mentioned in this application are considered to be incorporated integrally into the disclosure of this application so that they can serve as the basis for modifications if necessary. Furthermore, it should be understood that the above descriptions are merely preferred embodiments of this specification and are not intended to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification should be included within the scope of protection of one or more embodiments of this specification.

Claims

1. A steering wheel hands-off detection device, characterized in that, include: The first and second conductors are installed inside the steering wheel frame; The third and fourth conductors are disposed on the outside of the steering wheel frame, and the opposite portions of the first conductor and the third conductor form a first capacitor, and the opposite portions of the second conductor and the fourth conductor form a second capacitor; A control unit is configured to determine which of the user's hands is off-hand or both hands are off-hand simultaneously based on the capacitance changes of the first and second capacitors. The control unit includes first and second charging / discharging circuits and a control circuit, wherein the first and second charging / discharging circuits are electrically connected to the first and second conductors, respectively, and the control circuit is electrically connected to the first and second charging / discharging circuits. When the first and second charging / discharging circuits are activated, they charge and discharge the first and second capacitors respectively and detect the charging / discharging time to generate first and second output frequencies. The control circuit determines which of the user's hands is off-hand or both hands are off-hand simultaneously based on the changes in the first and second output frequencies. An ECG detection module, wherein one detection terminal of the ECG detection module is electrically connected to the third conductor, the other detection terminal of the ECG detection module is electrically connected to the fourth conductor, and the output terminal of the ECG detection module is connected to the control circuit; The ECG detection module detects the user's hand-off state through the third and fourth conductors. When the user's hand-off state is detected, the control circuit is controlled to start the first and second charging and discharging circuits for charging. When the control circuit determines that the user has removed both hands and then shakes hands again, it stops charging the first and second charging and discharging circuits, and the ECG detection module collects the ECG signal normally.

2. The steering wheel hands-off detection device as described in claim 1, characterized in that, The first and second conductors are insulated from the third and fourth conductors; The relative portions of the first conductor and the third conductor are arranged in parallel, and the relative portions of the second conductor and the fourth conductor are arranged in parallel.

3. The steering wheel hands-off detection device as described in claim 1, characterized in that, The first and second conductors are connected end to end, arranged around the steering wheel frame, and wrapped with an insulating layer.

4. The steering wheel hands-off detection device as described in claim 1, characterized in that, The first and second charging and discharging circuits are either first and second pulse generating circuits or first and second resonant circuits, respectively.

5. The steering wheel hands-off detection device as described in claim 1, characterized in that, The control circuit stores an initial frequency and is also used to compare the first and second output frequencies with the initial frequency respectively. When the first and second output frequencies change relative to the initial frequency, the control circuit determines which of the user's hands is in a hands-free state or both hands are in a hands-free state at the same time.

6. The steering wheel hands-off detection device as described in claim 1, characterized in that, The ECG detection module includes a resistor connected in series in the ECG detection circuit. When the detection circuit of the ECG detection module is broken, it determines that the user has removed their hand.

7. A vehicle, characterized in that, The device includes the steering wheel off-hand detection device as described in any one of claims 1-6.

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