Mistaken touch prevention automobile door outer handle based on mutual capacitance and automobile

Abstract

The utility model relates to a mistaken touch prevention automobile door outer handle based on mutual capacitance and an automobile. The mistaken touch prevention automobile door outer handle comprises a capacitance digital conversion circuit, a processor and a sensing unit. The sensing unit comprises at least four electrodes arranged on the handle, the outer surface, away from the vehicle body direction, of the handle serves as a sensing area, and at least three planar mutual capacitance induction electric fields used for sensing that an external object approaches and / or makes contact with the sensing area are formed among the electrodes; the central electric field in the at least three planar mutual capacitance induction electric fields is used as a main electric field, the rest electric fields are used as auxiliary electric fields, and the position, corresponding to the main electric field, of the outer surface of the handle on the sensing area is provided with a guide mark; the capacitance-to-digital conversion circuit is respectively coupled with each electrode; the processor is coupled to the digital conversion circuit. By means of at least three planar mutual capacitance induction electric fields formed by at least four electrodes, the problem of mistaken touch of a capacitance detection type automobile door outer handle is solved.

Description

Technical Field

[0001] This utility model relates to the automotive field, and in particular to an anti-accidental touch door handle based on mutual capacitance, and an automobile. Background Technology

[0002] Currently, most of the automotive industry has implemented "keyless entry systems," meaning car owners no longer need to rummage through their bags for keys. Simply approaching the car, the vehicle automatically senses the key in their bag. The owner then simply touches the sensor button on the door handle to unlock the door, providing a more convenient and secure driving experience. As an important component of the "keyless entry system," in addition to button-type keyless switches, the handle also offers a more intuitive capacitive touch switch, which activates the sensing circuit with a light touch.

[0003] The following two documents refer to patents that utilize this technology in the market:

[0004] (1) CN202211602933.9, “A Touch Control Method and Touch Processing System for a Hidden Door Handle,” mentions periodically collecting capacitance data, and the smart device storing historical capacitance data. A capacitance threshold is generated based on the collected historical capacitance data, and a capacitance difference is generated based on the average capacitance value and the current value. The opening and closing commands of the hidden door handle are generated through the capacitance threshold and the difference. This method is used to reduce the impact of environmental factors and long-term sensor use on the state judgment of the hidden door handle.

[0005] (2) CN202111315366.4, "A Multi-Contact Capacitive Electric Door Opening Control System and Method," introduces the principle of capacitance detection. It detects changes in capacitance based on the number of touches and determines whether the door opening condition is triggered based on the capacitance change signal. This replaces the traditional mechanical drive, eliminating the need for pressure to generate a signal. It enables the implementation of an intelligent door opening system at a low cost, extending the lifespan of the door lock.

[0006] As this technology was gradually applied, everyone solved the problem of applying capacitive sensing to car exterior door handles, but overlooked the problem of accidental touches on car exterior door handles. For example: 1. When it rains or the car is washed, water splashes on the car's capacitive sensing door handle, which can easily cause accidental touches and open the car door; 2. When a person or metal moves around or makes large-area contact with the car's capacitive sensing door handle, it can also cause the car door to open.

[0007] This invention aims to solve the problem of accidental activation of capacitive detection type automotive door handles. Utility Model Content

[0008] To address the shortcomings of existing technologies, this invention provides an anti-accidental touch vehicle door handle based on mutual capacitance.

[0009] The exterior door handle provided by this utility model includes a capacitance-to-digital conversion circuit, a processor, and a sensing unit. The sensing unit includes at least four electrodes disposed on the handle, with the outer surface of the handle away from the vehicle body serving as the sensing area. At least three planar mutual capacitance induced electric fields are formed between the electrodes to sense the approach and / or contact of external objects with the sensing area. The electric field at the center of the at least three planar mutual capacitance induced electric fields serves as the main electric field, and the remaining electric fields serve as auxiliary electric fields. A guide mark is provided on the outer surface of the handle in the sensing area corresponding to the position of the main electric field. The capacitance-to-digital conversion circuit is coupled to each electrode. The processor is coupled to the digital conversion circuit.

[0010] The exterior door handle provided by this utility model also includes the following auxiliary solutions:

[0011] Furthermore, all electrodes are located on the same plane.

[0012] As an optional implementation, the sensing unit includes a first electrode, a second electrode, a third electrode, and a fourth electrode. The first electrode, the second electrode, and the third electrode are arranged in parallel, and the fourth electrode is a transverse electrode. The fourth electrode is arranged above or below the first electrode, the second electrode, and the third electrode as a common electrode. The second electrode and the fourth electrode form a main electric field, the first electrode and the fourth electrode form a first auxiliary electric field, and the third electrode and the fourth electrode form a second auxiliary electric field.

[0013] As another optional implementation, the sensing unit includes a first electrode, a second electrode, a third electrode, and a fourth electrode arranged in a row or column, wherein the second electrode and the third electrode form a main electric field, the first electrode and the second electrode form a first auxiliary electric field, and the third electrode and the fourth electrode form a second auxiliary electric field.

[0014] As an alternative implementation, the electrodes form a multi-row, multi-column array; the electric field at the center of the array serves as the main electric field, corresponding to a guiding marker. Furthermore, the electrodes in each row are coupled to each other, and the electrodes in each column are coupled to each other; the exterior door handle includes a switch array, and the capacitor-to-digital converter circuit scans the rows and columns of the electrode array through the switch array. Each electrode in the array is rhomboid in shape. All electrodes have the same area and / or the spacing between them is the same.

[0015] Furthermore, the guide markers are placed at the geometric centers of the two corresponding electrodes that form the main electric field.

[0016] Furthermore, the exterior door handles are concealed to prevent accidental activation.

[0017] Another vehicle is provided, including the aforementioned anti-accidental-touch exterior door handle.

[0018] The door handle solution of this utility model can achieve the following beneficial effects by using at least three planar mutual capacitance induction electric fields formed by at least four electrodes: (1) the capacitance change law of the main electric field and auxiliary electric field formed by the finger clicking mark is different from that of rain, car washing or large-area human body approaching, so as to prevent accidental touch recognition; (2) the arrangement of electric fields allows for further perception of the wiping sequence, avoiding accidental opening of the door when wiping with a cloth or spraying water, which may cause damage to the car or passengers; (3) the mutual capacitance characteristics can be used to distinguish the changes in rainfall, which can be used as a basis for adjusting the sensitivity of the sensor and reducing the possibility of false triggering. Attached Figure Description

[0019] Figure 1 A schematic diagram of a capacitive sensing unit installed in a hidden door handle is provided.

[0020] Figure 2a An arrangement method using a common upper electrode to form parallel mutual capacitance is presented.

[0021] Figure 2b An arrangement method using a lower common electrode to form parallel mutual capacitance is presented.

[0022] Figure 3 A parallel four-electrode arrangement is presented.

[0023] Figure 4 The arrangement of the electrodes using a matrix electrode pattern is given. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0025] Reference Figure 1The exterior door handle 200 of this embodiment includes a built-in PCB board. The PCB board houses a capacitance-to-digital converter (DCC) circuit, a processor, and a capacitive sensing unit 201 constructed from distributed electrodes. The sensing unit 201 includes at least four electrodes disposed on the handle 200. The outer surface of the handle 200 away from the vehicle body serves as the sensing area. At least three planar mutual capacitance induced electric fields are formed between the electrodes to sense the approach and / or contact of external objects with the sensing area. The mutual capacitance electric fields are directed away from the vehicle body. The DCC circuit and the processor are coupled to each other. The DCC circuit is coupled to each electrode and acquires the change in self-capacitance on the corresponding electrode. The DCC circuit, such as using an ADI7142 or ADI7147, employs a Δ-Σ modulation method to directly convert the measured capacitance value into a digital value by repeatedly charging and discharging the measured capacitance and comparing it with a reference capacitance (see: US Patent Number: 5,134,401), thereby improving the measurement sensitivity of capacitance to the 1ff level and removing stray capacitance. In at least three planar mutual capacitance induced electric fields, the electric field located at the center is used as the main electric field, and the remaining electric fields are used as auxiliary electric fields. The outer surface of the handle 200 on the sensing area is provided with a guide mark 202 corresponding to the position of the main electric field, which can be used as a visual guide to guide the finger to touch. The guide mark 202 is set at or near the geometric center of the two corresponding electrodes that construct the main electric field. The closer it is to the geometric center, the greater the capacitance change can be obtained.

[0026] When a finger touches the marker 202, the capacitance of the main electric field changes the most, while the capacitance of the auxiliary electric field gradually decreases along the outward direction. However, regardless of whether it is raining, washing a car, or a large area of ​​a human body or metal is close, multiple points of capacitance will be triggered simultaneously, which cannot meet the above pattern, thus preventing accidental touches. When a user washes a car, the area of ​​the rag and the area of ​​the water spray gun can easily form a synchronous coverage of at least two mutual capacitance electric fields on the handle 200. The three electric fields further sense the wiping sequence, and these signals are used to prevent accidental touches. The mutual capacitance scheme can distinguish between heavy rain and light rain. The processor adjusts the switching threshold based on the rainfall change. When the capacitance change of the main electrode is greater than the threshold, the door is opened or closed. The switching threshold can modify the detection sensitivity by adjusting the rainfall, reducing the possibility of accidental triggering.

[0027] In the above scheme, the various electrodes can be located on the same plane or on different planes. A design on the same plane is beneficial for the consistency of capacitance change and facilitates manufacturing and installation; in a scheme with different planes, some computing power can be invested to compensate for the differences in capacitance change caused by the different planes through calibration.

[0028] Based on the premise that all electrodes are located on the same plane, the following three arrangements of planar electrodes are provided to achieve the formation of at least three planar mutual capacitance induced electric fields.

[0029] As the first electrode arrangement method, refer to Figure 2a , Figure 2b The sensing unit 201 includes a first electrode 301, a second electrode 302, a third electrode 303, and a fourth electrode 304. The first electrode 301, second electrode 302, and third electrode 303 are arranged side by side, and the fourth electrode 304 is a lateral electrode. The fourth electrode 304 is positioned above or below the first electrode 301, second electrode 302, and third electrode 303 as a common electrode. The second electrode 302 and the fourth electrode 304 form the main electric field. The guide mark 305 is located at the geometric center between the second electrode 302 and the fourth electrode 304. The first electrode 301 and the fourth electrode 304 form a first auxiliary electric field, and the third electrode 303 and the fourth electrode 304 form a second auxiliary electric field. This scheme simplifies electrode arrangement. The fourth electrode 304 serves as a common excitation, while the other three electrodes 301, 302, and 303 act as receivers, forming three parallel mutual capacitances. The three electric fields can coexist simultaneously, resulting in higher time resolution.

[0030] As a second electrode arrangement method, refer to Figure 3 The sensing unit 201 includes a first electrode 401, a second electrode 402, a third electrode 403, and a fourth electrode 405 arranged side-by-side in a row or column. The second electrode 402 and the third electrode 403 form the main electric field. The guide marker 404 is located at the geometric center between the second electrode 402 and the fourth electrode 403. The first electrode 401 and the second electrode 402 form a first auxiliary electric field, and the third electrode 403 and the fourth electrode 405 form a second auxiliary electric field. This arrangement is simple. A mutual capacitance is formed by two adjacent electrodes. The CDC collects data on each mutual capacitance in a time-division manner, achieving near-simultaneous capacitance change detection by leveraging the high frequency of the chip.

[0031] As a third electrode arrangement method, refer to Figure 4The electrodes form a multi-row, multi-column array, with the electric field at the center of the array serving as the main electric field and corresponding to the guide marker 509. For example, a 3-row, 5-column mutual capacitance detector is arranged on the door handle. When a finger enters the mutual capacitance, the row and column numbers of the capacitor with the largest change are indexed, thus determining the current finger-triggered position. Whether it's raining, washing a car, or a large area of ​​metal coming into contact with the body, multiple points of capacitance will be triggered simultaneously. This differs from the capacitance change pattern between the main and auxiliary electric fields when a finger is simply touching the surface, thus preventing accidental touches. Furthermore, for rows 501, 502, and 503, the electrodes in each row are mutually coupled; for columns 504, 505, 506, 507, and 508, the electrodes in each column are mutually coupled. A switch array is set on the PCB, and the capacitance-to-digital converter (CDC) circuit scans the rows and columns of the electrode array through the switch array. By scanning rows and columns using multiple capacitance electrodes, the state of each point on the car door handle 200 can be accurately determined using a limited number of CDC channels.

[0032] Building upon the third electrode arrangement, further, the shape of each electrode in the array is rhomboid, which more efficiently utilizes the limited PCB surface area to improve mutual capacitance detection sensitivity compared to rectangular or circular shapes. And / or, the area of ​​each electrode is the same and / or the spacing between each electrode is the same, further improving the consistency of capacitance changes.

[0033] The technology of this invention can be used in pull-type door handles 200 and also in concealed door handles 200. When applied to concealed door handles 200, since the electrodes sense the approach and / or contact of objects on the outer surface of the handle 200 away from the vehicle body, the switching operation can be performed on the outer surface of the handle 200, resulting in a more suitable fit for concealed door handles 200.

[0034] The capacitive solution of this invention has high accuracy, which improves the safety and reliability of capacitive sensors in automotive exterior door handles and avoids accidental triggering of the door handle 200, which could cause injury to the vehicle or passengers.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.

Claims

1. A door handle for preventing accidental touch based on mutual capacitance, characterized in that: Includes a capacitor-to-digital converter circuit, a processor, and a sensing unit; The sensing unit includes at least four electrodes disposed on the handlebar, with the outer surface of the handlebar away from the vehicle body serving as the sensing area, and at least three planar mutual capacitance induced electric fields arranged between each of the electrodes for sensing the approach and / or contact of external objects with the sensing area. The electric field at the center of at least three planar mutual capacitance induced electric fields is used as the main electric field, and the other electric fields are used as auxiliary electric fields. The outer surface of the handle on the sensing area is provided with a guide mark corresponding to the position of the main electric field. The capacitor-to-digital converter circuit is coupled to each electrode separately; The processor is coupled with a digital-to-digital converter circuit.

2. The anti-accidental touch door handle according to claim 1, characterized in that: All electrodes are located in the same plane.

3. The anti-accidental touch door handle according to claim 2, characterized in that: The sensing unit includes a first electrode, a second electrode, a third electrode, and a fourth electrode. The first electrode, the second electrode, and the third electrode are arranged side by side, and the fourth electrode is a horizontal electrode. The fourth electrode is arranged above or below the first electrode, the second electrode, and the third electrode as a common electrode. The second electrode and the fourth electrode form a main electric field, the first electrode and the fourth electrode form a first auxiliary electric field, and the third electrode and the fourth electrode form a second auxiliary electric field.

4. The anti-accidental touch door handle according to claim 2, characterized in that: The sensing unit includes a first electrode, a second electrode, a third electrode, and a fourth electrode arranged in a row or column. The second electrode and the third electrode form a main electric field, the first electrode and the second electrode form a first auxiliary electric field, and the third electrode and the fourth electrode form a second auxiliary electric field.

5. The anti-accidental touch door handle according to claim 2, characterized in that: The electrodes are arranged in a multi-row, multi-column array; The electric field located at the center of the array serves as a guide marker for the main electric field.

6. The anti-accidental touch exterior door handle according to claim 5, characterized in that: The electrodes in each row are coupled to each other, and the electrodes in each column are coupled to each other; It includes a switch array, and the capacitor-to-digital converter circuit forms a row and column scan of the electrode array through the switch array.

7. The anti-accidental touch door handle according to claim 5, characterized in that: The shape of each electrode in the array is rhomboid.

8. The anti-accidental touch door handle according to claim 4 or 5, characterized in that: All electrodes have the same area and / or the spacing between all electrodes is the same.

9. The anti-accidental touch vehicle door handle according to any one of claims 1-7, characterized in that: The guide markers are placed at the geometric center of the two corresponding electrodes that form the main electric field.

10. The anti-accidental touch door handle according to claim 1, characterized in that: The exterior door handles are concealed to prevent accidental activation.

11. A car, characterized in that, Includes the anti-accidental touch door handle as described in any one of claims 1-10.

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