Classifications

• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
  • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
  • H03K17/96—Touch switches
  • H03K17/962—Capacitive touch switches
  • H03K17/9622—Capacitive touch switches using a plurality of detectors, e.g. keyboard
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R25/00—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles
  • B60R25/20—Means to switch the anti-theft system on or off
  • B60R25/23—Means to switch the anti-theft system on or off using manual input of alphanumerical codes
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/016—Input arrangements with force or tactile feedback as computer generated output to the user
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/02—Input arrangements using manually operated switches, e.g. using keyboards or dials
  • G06F3/0202—Constructional details or processes of manufacture of the input device
  • G06F3/0219—Special purpose keyboards
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
  • H03K2217/94—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
  • H03K2217/96—Touch switches
  • H03K2217/96062—Touch switches with tactile or haptic feedback
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
  • H03K2217/94—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
  • H03K2217/96—Touch switches
  • H03K2217/9607—Capacitive touch switches
  • H03K2217/960705—Safety of capacitive touch and proximity switches, e.g. increasing reliability, fail-safe

Definitions

• the present invention relates to a method of managing a capacitive keyboard equipping a motor vehicle.
• the invention also relates to a motor vehicle comprising a capacitive keyboard and an electronic control unit configured to implement such a method.
• the field of the invention is that of capacitive keypads fitted to motor vehicles, in particular for unlocking or locking the doors.
• US2015360646A1 describes another example of a system for locking and unlocking the doors of a vehicle.
• the system comprises two user interfaces, grouped on a single capacitive keyboard or distributed over two different capacitive keyboards.
• the purpose of the present invention is to provide an improved method of managing a capacitive keyboard, especially in case of rain.
• the subject of the invention is a method for managing a capacitive keyboard fitted to a motor vehicle, the capacitive keyboard comprising several keys connected to an electronic control unit and having a tactile function, the method being characterized in that it comprises steps of: performing a capacitance measurement for each of the keys; and temporarily disable the touch function of the keyboard if, for at least one of the keys, the capacitance is greater than or equal to a predetermined threshold value.
• the invention makes it possible to improve the operation of the capacitive keyboard in the event of a downpour.
• the presence of water droplets on the keys increases the capacitance.
• the presence of a large drop of water on one of the keys is likely to decrease the capacitance and to be detected as a "false support" on this key.
• the touch function of the capacitive keyboard is deactivated at the beginning of the shower, which makes it possible to avoid false detections due to striking or the formation of large drops of water on the keys.
• the method also comprises a step of reactivating the keyboard's tactile function if, for all the keys, the capacitance is lower than the predetermined threshold value for a predetermined duration.
• the predetermined duration is 300 milliseconds.
• the predetermined threshold value is set 5% higher than a reference value of the capacitance, corresponding to the keys at rest.
• the capacitance measurement is performed via electrodes positioned under the keys and connected to the electronic control unit.
• the capacitance measurement is performed at regular intervals.
• the invention also relates to a motor vehicle, comprising a capacitive keyboard and an electronic control unit configured to implement the method defined above.
• Figure 1 is a front view of an outer part of motor vehicle door trim, comprising a capacitive keyboard connected to an electronic control unit;
• FIGS. 3 to 6 show graphs illustrating different signals transmitted to the electronic control unit, as a function of the stresses exerted on the surface of a key of the keyboard.
• a capacitive keyboard 10 equipping a door trim part 2 ("capping" in English) of a motor vehicle 1.
• the keyboard 10 comprises five keys 1 1, 12, 13, 14 and 15 connected to an electronic control unit 20 also equipping the outer trim piece 2.
• the unit 20 is itself connected to the on-board computer. Vehicle 1. In practice, the unit 20 must be as close as possible to the keyboard 10 to be able to detect in good conditions a capacitance variation of the electrodes, as explained below. Alternatively, the unit 20 can be integrated directly into the on-board computer of the vehicle 1.
• the keyboard 10 has a touch function, known per se.
• the keys 1 1 -15 are accessible on the outer surface 3 of the outer cladding part 2. Thus, a user can generate signals to the electronic control unit 20 by pressing on the surface of the keys 1 1 - 15.
• These signals are intended in particular to control the opening or closing of the doors of the vehicle 1, by typing a code corresponding to a predetermined sequence of support on the keys 1 1 -15.
• the touch function of the keyboard 10 is activated by default, but can be disabled under certain conditions, as detailed below.
• the keyboard 10 is a capacitive system, known per se.
• the keyboard 10 has a capacitive layer, designed to accumulate electrical charges. When the user touches the surface of the keyboard 10 with his finger, some of these charges are transferred to him. The charges leaving the capacitive layer create a quantifiable deficit, thus making it possible to detect a pressing on a given key 1 1 -15.
• the variations in charges can be measured by means of electrodes positioned under the keyboard 10 and connected to the unit 20.
• the capacitance C associated with each key 1 1 -15 can be measured and transmitted to the unit 20, either continuously, ie at regular intervals.
• the keys 1 1 -15 each comprise two digits, namely the numbers “1" and “2” for the key 1 1, the numbers “3” and “4" for the key 12, the numbers “5" and “6” For key 13, the numbers “7” and “8” for the key 14, and the numbers “9” and "0” for the key 15. This makes the keyboard 10 more compact, compared to a keyboard with ten keys.
• a sequence of pressing the keys 1 1 -15 thus sends a digital code to the unit 20, which then controls the opening or closing of the doors when the code is correct.
• pressing the key 1 1 sends the unit 20 a signal corresponding to both digits "1" and "2" indistinctly, and so on for the keys 12 to 15. This makes it possible to define a numerical code based on out of ten numbers, without the need for double support to type the even numbers.
• the keyboard 10 also comprises non-capacitive spaces 16 and 17, located respectively above the key 1 1 and below the key 15.
• the spaces 16 and 17 may be capacitive and constitute keys corresponding to the key.
• the keyboard 18 also comprises a light-emitting diode 18 located between the key 1 1 and the space 16, for example to indicate to the user that the support he has exerted on a key 1 1 -15 has been detected by the unit 20.
• FIGS. 3 to 6 show graphs illustrating various signals transmitted to the electronic control unit 20 from a given key 1 1 -15, as a function of the stresses exerted or not on the surface of this key.
• the abscissa axis corresponds to a time T in seconds (s), while the ordinate axis corresponds to a capacitance C in picofarads (pF).
• a reference value C0 and a threshold value C1 are shown in dotted lines.
• the reference value C0 depends in particular on the construction of the keyboard 10, the arrangement of the measurement electrodes, and the parameterization of the control unit 20. In the example of the figures, this reference value C0 is equal to 5pF .
• the threshold value C1 is predetermined during the setting of the control unit 20, according to the desired sensitivity to activate the anti-touch function of the keyboard 10. In the example of the figures, this threshold value C1 is defined as 5% higher. at the reference value C0, that is to say equal to 5.25 pF.
• Figure 3 is illustrated a signal C10 corresponding to a key 1 1 -15 at rest, transmitted to the unit 20 when the key receives no external stress.
• the capacitance C of the signal C10 varies slightly around the reference value C0. Indeed, the reference value CO is the theoretical value of the capacitance C at rest, while the signal C10 is generated from actual measurements of the capacitance C at rest.
• FIG. 4 is illustrated a signal C20 corresponding to two successive supports A1 and A2 on a given key 1 1 -15. While the user presses this key, capacitance C decreases by about 20%, temporarily from 5 to 4 pF.
• the unit 20 is configured to interpret each capacitance variation C and thus detect the supports A1 and A2.
• FIGS. 5 and 6 show a signal C30 recorded during a shower, for a given key 1 1 -15. These graphs comprise different phases B0, B1, B2, B3, B4, B5, B6, B7 and B8 distinct. For the sake of simplification, the measurement of time resumes at 0 on the graph of FIG. 6, it being understood that the phase B3 is prolonged on the two graphs of FIGS. 5 and 6.
• Phase B0 represents the very beginning of the downpour
• phase B1 represents the first seconds of the downpour.
• Raindrops fall on the keyboard 10, or run over the surface 3 of the outer trim piece 2 to the keyboard 10.
• the presence of water droplets on the keys 1 1 -15 increases the capacitance C.
• the presence of a large drop of water on the one of the keys 1 1 -15 is likely to decrease the capacitance C and to be detected as a "false support" on this key.
• the invention therefore aims to temporarily disable the touch function of the keyboard 10 during a shower to avoid false detection.
• Phase B2 represents the moment when the capacitance C of the signal C30 reaches the predetermined threshold value C1.
• the unit 20 temporarily disables the touch function of the keyboard 10.
• the unit 20 temporarily activates the anti-touch function of the keyboard 10.
• the unit 20 is configured to temporarily disable the touch function if the capacitance C is greater than or equal to the threshold value C1 for at least one of the keys 1 1 -15.
• Phase B3 represents the continuation of the downpour, while more and more water droplets trickle on the keyboard 10.
• the capacitance C signal C30 increases or decreases depending on the presence of droplets on this key.
• Phase B4 represents the moment when the downpour drops in intensity, while phase B5 represents the progressive cessation of the downpour.
• the water droplets still run on the keyboard 10, but do not accumulate on the keys 1 1 -15.
• Phase B6 represents the moment when the capacitance C of the signal C30 again reaches the threshold value C1 and goes back below.
• the unit 20 is configured to reactivate the touch function of the keyboard 10 if, for all the keys 1 1 -15, the capacitance C is less than the threshold value C1 during a predetermined period T1.
• the duration T1 can be fixed at 300 milliseconds.
• Phase B7 represents the moment when the duration T1 has elapsed since phase B6, for key 1 1 -15 corresponding to signal C30. If the capacitance C is still greater than or equal to the threshold value C1 for other keys, then the unit 20 maintains the deactivation of the tactile function of the keyboard 10. If the capacitance C has fallen back below the threshold value C1 during a duration T1 for each of the keys 1 1 -15, then the unit 20 reactivates the tactile function of the keyboard 10.
• phase B8 represents the progressive return to rest of the key 1 1 -15 corresponding to the signal C30.
• the keyboard 10 may be shaped differently from Figures 1 and 2, while the management method of the keyboard 10 may be implemented differently from Figures 3 to 6, without departing from the scope of the invention.
• the management method and the keyboard 10 can be adapted in terms of functionalities, performance and cost of implementation.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Human Computer Interaction (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Input From Keyboards Or The Like (AREA)
• Push-Button Switches (AREA)
• Electronic Switches (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=55542887

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (10)

• 2015
  • 2015-12-22 FR FR1563150A patent/FR3045984B1/fr not_active Expired - Fee Related
• 2016
  • 2016-12-13 US US16/064,489 patent/US20190007044A1/en not_active Abandoned
  • 2016-12-13 CN CN201680075403.XA patent/CN108463950A/zh active Pending
  • 2016-12-13 WO PCT/FR2016/053347 patent/WO2017109331A1/fr unknown
  • 2016-12-13 EP EP16825484.5A patent/EP3394984A1/fr not_active Withdrawn

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