GB2427039A

GB2427039A - A method for pre-heating a seat for a vehicle based on the available power of a battery

Info

Publication number: GB2427039A
Application number: GB0608570A
Authority: GB
Inventors: Robert Alan Palin
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2003-08-21
Filing date: 2003-08-21
Publication date: 2006-12-13
Anticipated expiration: 2023-08-21
Also published as: GB0608570D0; GB2427039B

Abstract

A method of pre-heating an electrically heated seat in which a controller is programmed to switch on the heater before a person enters the vehicle. The seat will only be heated if sufficient stored power is available from a battery. The heating may be switched off if the seat is un-occupied after a pre-determined time. Seat occupancy may be determined by monitoring a door and seat load sensors. The need for seat heating may be determined by monitoring the ambient temperature.

Description

A Method for Controlling the Heating of a Seat for a Motor Vehicle This

invention relates to heated seats for motor vehicles and in particular to a method for pre-heating a heated seat.

It is well known, for example, from US Patent number 6, 093, 910 to provide a mechanism for electrically heating one or more seats of a motor vehicle to improve occupant comfort in cold weather. In a typical seat a heating element is positioned in the base of the seat and is covered by a layer of foam upon which an occupant can sit.

According to the invention there is provided method for pre-heating an electrically heated seat for a motor vehicle having a battery, the method comprising the steps of: - determining that seat heating is likely to be required, - determining whether the battery has sufficient stored electrical power to supply the seat heater, and - if sufficient energy is available from the battery, switching on the seat heater before a person enters the motor vehicle.

The method may further comprise switching off the seat heater after a predetermined time delay if actual seat occupancy has not been confirmed.

Actual seat occupancy may be determined by monitoring the output from at least one of a door sensor and a seat load sensor.

The step of determining that seat heating will be required may further include monitoring the ambient temperature to determine whether it is below a pre-determined level.

The invention will now be described by way of example with reference to the accompanying drawing of which:- Fig.1 is a block diagram of a heated seat and control system commonly found on modern motor vehicles; and Fig.2 is a flowchart showing a method of pre-heating a vehicle seat according to the invention; With particular reference to Fig.1 there is shown a motor vehicle having a system 10 for controlling the heating and pre-heating of a vehicle seat 5. The seat 5 is fitted with an electric heater 8 and means are provided in the form of a load sensor 27 to sense the weight of an occupant seated on the seat 5. A temperature sensor 28 is provided to measure the temperature within the core of the seat 5.

The seat heater 8 receives power from a heater power controller 22 which is controlled by an electronic controller 20. A source of electrical power in the form of a battery 24 is provided to power the electronic controller 20 and all of the other components of the system 10 requiring electrical power.

The electronic controller 20 receives input signals from the load sensor 27 and the temperature sensor 28.

An occupant controllable device in the form of a switch 23 is provided to allow an occupant of the motor vehicle to override the electronic controller 20 and switch on or off the seat heater 8 at any time. As shown the switch 23 is a simple on/off device but it will be appreciated that the switch could have several additional positions setting various levels of heating for the seat 5.

The electronic controller 20 is operationally arranged to receive the signal from the load sensor 27 and to control the seat heater 8 accordingly. It will be appreciated that the electronic controller 20 can directly control the seat heater 8 or, as shown, use a power controller such as the heater power controller 22 to control the power supplied to the seat heater 8.

The control system 10 includes means to pre-heat the seat 5 so that the seat 5 has already started to warm-up before a person enters the motor vehicle.

This is achieved by using the electronic controller 20 to monitor the output from an ambient temperature sensor 21, a means for determining whether the seat 5 is likely to be occupied such as a door lock sensor 25 associated with a door lock 7 fitted to a door 6 of the motor vehicle and a means for confirming that the seat 5 has actually been occupied such as a door entry sensor 26.

It will be appreciated that instead of the door lock sensor the electronic controller 20 could monitor the output from a remote door locking device or from any other suitable device providing an indication that the motor vehicle is about to be occupied.

Similarly, although the opening of the door 5 as sensed by the door entry sensor 26 is a convenient way of confirming that actual seat occupancy has taken place, it will be appreciated that the load sensor could also be used to perform this task and that other devices such as thermal and ultrasonic sensors used in safety systems to detect the presence of an occupant could also be used.

Operation of the system is best understood with reference to the flowchart shown in Fig.2 which is a skeletal representation of the logic used by the electronic controller 20 to perform the pre-heating of the seat 5.

The first step is the determination of whether entry is anticipated. This is achieved by monitoring the output from the door lock sensor 25. If a door unlock signal is received then the electronic controller 20 uses this as an indication that imminent occupation of the seat 5 is likely. If no unlock signal is sensed then the electronic controller 20 continues to monitor the output from the door lock sensor 25 but takes no other action.

The next stage is to determine whether seat heating is required. This is done by using the output from the ambient air temperature sensor 21 which provides an indication of the ambient temperature of the air in the cabin of the motor vehicle or surrounding the motor vehicle. When this temperature is above a pre-determined limit no seat heating is required and the system is operable to terminate without switching on the seat heater 8. This pre- determined temperature will depend on the environment in which the motor vehicle is used but is typically in the range 5 to 15 C.

If the temperature is below the pre-determined limit then the next stage is to determine whether the battery 24 has sufficient stored electrical power to supply the seat heater 8 while retaining reserves for engine starting and other essential electrical demands.

If sufficient energy is not available then the system terminates without switching on the seat heater 8.

If sufficient energy is available from the battery 24 then the electronic controller 20 is operable to switch on the seat heater 8 and simultaneously starts a timer running.

The next stage is to determine whether the seat is actually occupied, this is done by monitoring whether the door 6 opens during the period when the timer is running by monitoring the output from the door entry sensor 26. If the door 6 does open during the period when the timer is running then this is used by the electronic controller 20 as a confirmation of actual seat occupation and the seat heater 8 is kept on. If no signal is received from the door entry sensor 26 during the period when the timer is running then this is used by the electronic controller 20 as an indication that the seat 5 has not been occupied and the seat heater 8 is switched off to prevent the battery 24 from being unnecessarily depleted.

It will be appreciated by the man skilled in the art that this invention has been described by way of example with reference to specific embodiments of the invention but that it is not so limited and that various modifications or alternative embodiments could be made without departing from the scope of the invention.

For example, although the invention has been described with reference to a seat having an electrical heater fitted in the seat it is applicable to an electrical heater remotely mounted supplying heated air to the seat through a conduit.

Claims

1. A method for pre-heating an electrically heated seat for a motor vehicle having a battery, the method comprising the steps of: determining that seat heating is likely to be required, - determining whether the battery has sufficient stored electrical power to supply the seat heater, and - if sufficient energy is available from the battery, switching on the seat heater before a person enters the motor vehicle.

2. A method as claimed in claim 1 wherein the method further comprises switching off the seat heater after a pre-determined time delay if actual seat occupancy has not been confirmed.

3. A method as claimed in claim 2 wherein actual seat occupancy is determined by monitoring the output from at least one of a door sensor and a seat load sensor.

4. A method as claimed in any of claims 1 to 3 wherein the step of determining that seat heating will be required further includes monitoring the ambient temperature to determine whether it is below a pre- determined level.

5. A method for pre-heating an electrically heated seat for a motor vehicle substantially as described herein with reference to the accompanying drawing.