FIELD

The present disclosure relates generally to an entry system for motor vehicles and, more particularly to a capacitive touch pad with mechanical emergency switch assembly for an electronic vehicle entry system. The present disclosure also relates to a method of operating the vehicle entry system.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

It is known that electrical latches (e-latch) are provided in motor vehicles, for example, for controlling the opening and closing of various closure panels such as passenger doors and lift gates. One of the defining characteristics of an e-latch is that it does not include a mechanical linkage to an outside or inside door handle. Instead, the door is released by a power-operated actuator in response to an electrical signal coming from one of the handles. The e-latch generally includes a latching mechanism having a ratchet that is selectively rotatable with respect to a striker fixed to a door post in order to latch and unlatch the door. The latching mechanism also generally includes a pawl that selectively engages the ratchet to prevent the ratchet from rotating. The e-latch also typically includes a power-operated actuator, such as an electric motor, which is electrically connected to a main power supply of the vehicle (e.g., the 12V battery of the vehicle) in order to directly or indirectly drive the pawl.

Because a common problem related to e-latches is that of controlling opening and closing of the doors or closure members in the case of a failure of the main power supply, a backup power source for the e-latch can be provided to supply electrical energy to the electric motor of the latch. EP 0 694 664 A1 discloses a backup energy source for an electrical door latch designed to supply power to the latch during emergency situations and which includes an auxiliary battery arranged within the door in order to power the release of the striker from the ratchet to facilitate opening of the door by the vehicle occupant. WO2014/102282 discloses a backup energy source for an electrical door latch that is designed to supply power to the electric motor during emergency situations and which includes a super capacitor group configured to store energy during normal operating conditions and supply a backup supply voltage to the electric motor during failure operating conditions.

Additionally, door opening/closing systems are moving towards the elimination of traditional mechanical handles/unlock switches by replacing such door handles/unlock switches with electronic sensors i.e. touch pad entry/touchless sensors. For example, a capacitive touch pad may be provided to replace an external handle or unlock switch which is in communication with the electronic latch to command the unlatching/opening of the latch. As part of such an electronic entry system, a door unlatch may be commanded with a “soft touch” on the capacitive touch pad/sensor (i.e. the capacitive touch pad requests a door unlatch to the e-latch through a hardwire connection or via the communication bus between the capacitive touch pad and the e-latch).

Capacitive sensors require power to operate, and thus due to the possibility of power failures or failure of the touch pad/sensor, the physical handle cannot fully be replaced by the touch pad since the door or closure member must still be able to be opened in the case of a failure in the operation of the entry sensor/system. For example, in the event of a lack of power (i.e. battery disconnect, dead battery, broken wire, or even a broken sensor) the door cannot be opened from the outside since the sensor and sensor microcontroller cannot be powered. In the case where a backup power system is provided, the entry sensors still may draw significant power to deplete the back-up energy source.

Accordingly, there remains a need for improved touch pads for entry systems used on motor vehicles and methods of operation thereof that allow a user to directly command the operation of the electronic latch in the case of an operational failure of the electronic entry sensor.

SUMMARY

This section provides a general summary of the present disclosure and is not a comprehensive disclosure of its full scope or all of its features and advantages.

It is an object of the present disclosure to provide an entry system and a touch pad for the entry system for use in a motor vehicle that addresses and overcomes the above-noted shortcomings.

Accordingly, it is an aspect of the present disclosure to provide a touch pad for operating an e-latch assembly of a motor vehicle entry system including a control circuit having a backup energy source. The touch pad includes a touch pad controller in communication with the control circuit of the e-latch assembly. The touch pad also includes at least one entry input sensor coupled to the touch pad controller for outputting a signal indicative of a command to operate the e-latch assembly. Finally, the touch pad includes a mechanical emergency switch assembly adjacent the at least one entry input sensor and including a plurality of pins electrically coupled to the control circuit of the e-latch assembly for operating the e-latch assembly when the at least one entry input sensor is not operable due to one of a power loss and malfunction of the at least one entry input sensor.

According to another aspect of the disclosure, an entry system for a closure member of a motor vehicle is also provided. The entry system includes an e-latch assembly that has a control circuit including a control unit normally powered by a main power source of the motor vehicle. The control circuit is configured to operate an actuation group operable to control actuation of the closure member. The control circuit of the e-latch assembly includes a backup energy source to provide power to the control unit and the actuation group in the event of a loss of power from the main power source. The entry system also includes a touch pad that has a touch pad controller in communication with the control circuit. The touch pad also includes at least one entry input sensor coupled to the touch pad controller for outputting a signal indicative of a touch to operate the e-latch assembly. The touch pad includes a mechanical emergency switch assembly adjacent the at least one entry input sensor. The mechanical emergency switch assembly includes a plurality of pins electrically coupled to the control circuit of the e-latch assembly for operating the e-latch assembly when the at least one entry input sensor is not operable due to one of a malfunction of the at least one entry input sensor and the loss of power from the main power source.

According to yet another aspect of the disclosure, a method of operating an entry system of a motor vehicle including an e-latch assembly, is also provided. The method begins with the step of monitoring a battery voltage and the entry system continuously using a control circuit of the e-latch assembly in a non-emergency mode. The next step of the method is providing power to the control circuit in the event of a loss of power from a main power source using a backup energy source of the control circuit. The method proceeds by determining one of the loss of power from the main power source and a failure of a component of the entry system using the control circuit. The method continues with the step of transitioning to an emergency mode in response to determining one of the loss of battery power and the component failure of the entry system. The method also includes the step of polling a plurality of pins of a mechanical emergency switch assembly of a touch pad associated with a closure member of the vehicle using the control circuit for the actuation of the mechanical emergency switch assembly in the emergency mode. The next step is determining whether the actuation from the plurality pins of the mechanical emergency switch assembly indicate a command from a user to unlatch the closure member using the control circuit in the emergency mode. The method concludes with the step of operating an actuation group associated with the e-latch assembly with the control circuit using power from the backup energy source of the control circuit in response to determining that the actuation from the plurality pins of the mechanical emergency switch assembly indicate the command from the user to unlatch the closure member in the emergency mode.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

