DE102011123117B3 - Reducing the power of a heating device of a motor vehicle when reaching or falling below a defined distance or time period up to the stop point - Google Patents

Abstract

Method for reducing the power of a heating device (1) of a motor vehicle, with the following steps: - determining the distance (Δs) or duration (Δt) to a stop point; - reducing the power of the heating device (1) when reaching or falling below a defined distance (Δsth) or defined time period (Δtth) up to the stop point, the power of the heating device (1) being reduced in such a way that the power decreases with decreasing distance (Δs) or duration (Δt) to the stop point, and the stop point is estimated by means of a route destination estimator.

Description

The invention relates to the setting of the output of a heating device of a motor vehicle.

In today's motor vehicles, a heating device (for example a seat heater) that has been activated is operated until the vehicle is parked as long as the driver does not deactivate the heating device.

In the case of a system with thermal inertia, however, from the driver's point of view there is no significant advantage in operating a heating device once it has been activated until the vehicle is parked. Instead, this increases fuel consumption unnecessarily.

From the pamphlet DE 10 2004 008 972 A1 it is known that the air conditioning system of a motor vehicle is automatically switched off when a certain distance is reached from the destination. If the air conditioning is switched off before reaching the destination, only the fan will run, so that moisture is removed from the refrigerant evaporator of the air conditioning. When the vehicle is started up again, the air conditioning can then be used without the windows fogging up.

In the pamphlet DE 10 2008 051 975 A1 describes how to determine the remaining travel time of the vehicle to the destination and to switch off the cooling circuit of the air conditioning system in good time before reaching the destination, the fan then continuing to run. This causes the fan to completely dry out the heat exchanger and the air duct system.

For further state of the art, see DE 10 2006 057 275 A1 , DE 10 2007 007 487 A1 , JP 2005 - 354 761 A , US 2010/0332 130 A1 and DE 10 2008 021 045 A1 referenced.

The object of the invention is to specify a method and a corresponding device for setting the power of a heating device of a motor vehicle, which is characterized by a reduction in energy consumption without the driver noticing the energy-saving measure as a loss of comfort.

The object is achieved by the features of the independent patent claims.

The present invention is based on the fact that information about the probable stop of the vehicle is used in order to undertake a premature performance degradation of one or more heating devices.

A first aspect of the invention relates to a method for reducing the output of a heating device of a motor vehicle. The heating device is preferably an electrically operated heating device, for example a seat heater, a window heater (for example for the front or rear window), an exterior mirror heater or a steering wheel heater. According to the method, the distance or time period up to a stop point is determined in particular repeatedly. When a defined distance or defined period of time up to the stop point is reached, the output of the heating device is reduced. Alternatively, it can also be checked whether a defined distance or time has been exceeded in order to then reduce the power.

By reducing the power prematurely before reaching the goal, energy is saved. In a conventional motor vehicle with an internal combustion engine, which drives, for example, an electrical generator (alternator) to generate electrical energy, the measure according to the invention saves _{fuel and thus reduces CO 2 emissions.}

Because the thermal system reacts sluggishly and therefore a noticeable decrease in temperature can only occur a certain time after the reduction in performance, the driver hardly notices the reduction in performance, or not at all.

The performance degradation described can be implemented at low additional costs by expanding the software for controlling the heating device.

The stop point can be, for example, the destination of the route (for example when driving home or to work) or a stop point with a longer dwell time, for example in the case of a longer stopover at a motorway service station or a shopping center.

For example, it can be provided that the output of the heating device when reaching or falling below a defined time period Δt _th with Δt _th <300 s (e.g. Δt _th = 60 s or Δt _th = 120 s) or a defined distance Δs _th with Δs _th <6000 m (e.g. Δs _th = 1000 m) is reduced up to the stop point.

Not only the output of a single heating device, but also the output of a plurality of heating devices (for example seat heating and steering wheel heating) can be reduced when reaching / falling below a defined distance or defined period of time until the stop point.

The heating device can be completely deactivated when reaching / falling below the defined distance or defined period of time; in this case the heating power is reduced to zero or almost zero. Alternatively, the output of the heating device can only be reduced to a lower value than before when the defined distance or time period is reached / undershot before the stop point, without completely deactivating the heating function.

The method according to the invention typically uses a satellite-based navigation system in order to determine the distance or time until the stopping point. However, a navigation system is not essential.

According to the invention, a route destination estimator is used which estimates the destination, for example on the basis of a comparison of the driven route with stored routes. For example, a route destination estimator can be used, which is used in a similar form, for example in the project “iLeNa - intelligent learning navigation”. Here it is saved who is driving the vehicle on which day at which time and on which route to which destination. Using this stored information, the system can estimate the most likely destination with a high probability of being hit after a large number of journeys.

It can be provided that the degradation of the heating function is reversed again; For example, the output of the heating device can be increased again if the driver continues to drive after reaching a destination (for example his own apartment) or if the driver drives to another destination (for example a supermarket) before the expected destination (for example his own apartment).

According to a preferred embodiment, the function can optionally be activated and deactivated by the driver.

The extent of the power reduction can be variable.

The size of the power reduction or, if a plurality of heating devices are included, the number of devices affected by the power reduction can be variable. In addition, depending on one or more boundary conditions, the power reduction can also be completely omitted when the defined distance or time period is reached / undershot. For example, if a rain sensor detects rain, the automatic switch-off of a front or rear window heater can be prevented. The expected driving behavior of the driver can also have an influence on the power reduction: For example, the power reduction of the heated rear window can be prevented in the event that the driver is expected to reverse into parking at the destination. In addition, it can be provided that the power reduction is not carried out or is carried out only to a limited extent (for example only slight power reduction instead of complete deactivation) as long as a necessary minimum running time of the heating device has not been reached.

According to the invention, the power of the heating device is reduced in such a way that the power decreases with decreasing distance or duration up to the stop point.

According to a further embodiment of the invention, it can be provided that, in addition to the degradation of the heating device's power, the charging power of an electrical energy store in the vehicle is increased. When reaching / falling below the defined distance or defined time period up to the stop point, not only is the output of the heating device reduced, but also the charging output is increased. For example, before reaching the defined distance or period of time, the generator power can be 1 kW, with a power of 800 W being used to feed one or more heating devices and a power of 200 W being used to charge the electrical energy store. After reaching the defined distance or period of time, for example, the output of the one or more heating devices is then reduced to 500 W and the electrical energy storage device is charged with an output of 500 W instead of an output of 200 W. This procedure can be used with conventional vehicles without an electric drive, with hybrid vehicles (especially with plug-in hybrid vehicles, which can be connected to an electrical power supply network to charge the battery) or electric vehicles. Increasing the charging power is particularly useful, for example, when the energy storage device is weakly charged, as can often be the case, for example, on extremely short journeys, or if there is no recharging at the destination (for example at home).

It can be provided that if recharging takes place, for example, at home, the energy storage content is reduced. Provision can also be made for the charging power to be reduced when stationary recharging is expected, for example at home.

It would also be conceivable to carry out the approaches described above for controlling the charging power, in particular increasing the charging power as a function of the remaining distance or time until the stop point, without reducing the heating power.

A second aspect of the invention relates to a device for adjusting the power of a heating device of a motor vehicle. The device comprises means for determining the distance or time to a stop point; a satellite-based navigation system can be used for this purpose, for example. In addition, control means are provided which are used to reduce the output of the heating device when reaching or falling below a defined distance or defined period of time up to the stop point.

The above statements on the method according to the invention according to the first aspect of the invention also apply in a corresponding manner to the device according to the invention for setting the power according to the second aspect of the invention.

The invention is described below with the aid of the accompanying drawing using an exemplary embodiment.

In this drawing is a device for adjusting the power of an electrically operated heating device 1 a motor vehicle shown. At the heater 1 it is, for example, seat heating, window heating, exterior mirror heating or steering wheel heating. The heater 1 is from an electrical source 3 supplied with electrical power. The from heater 1 power consumed by the electrical source 3 is via an actuator 2 set. Typically in electrical heating devices is an actuator 2 to regulate the electrical power anyway. In the simplest case, it can be the actuator 2 a switch between the heater 1 and the electrical source 3 act, with the heater in the open state 1 is deactivated.

There is also a satellite-based navigation system 4th provided, which continuously determines the distance Δs or duration Δt up to a stop point. The user places the stop point in the navigation system, for example 4th has been entered. Alternatively, it can also be provided that the stop point is estimated by means of a route destination estimator.

A control unit 5 continuously takes the from the navigation system 4th delivered current distance Δs or time duration Δt and compares the respective current value with a comparison value Δs _th or Δt _th , which corresponds to a defined distance or time duration up to the stop point. The comparison value Δs _th or Δt _th can be constant or be determined variably. When the distance Δs _th or the time duration Δt _{th is reached} before the stop point (ie Δs Δs _th or Δt Δt _th ), the control unit initiates this 5 a degradation in performance (in particular a deactivation) of the heating device 1 and controls the actuator 2 for this purpose via a corresponding control signal 6th on. For example, when using a simple switch as an actuator 2 the performance degradation takes place by opening the switch. Alternatively, the power degradation of the heating device can only occur when the distance Δs _th or duration Δt _th (ie Δs <Δs _th or Δt <Δt _{th) is not reached} 1 be initiated.

Claims (3)

Method for reducing the output of a heating device (1) of a motor vehicle, comprising the steps of: determining the distance (Δs) or time duration (Δt) up to a stop point; - Reducing the power of the heating device (1) when reaching or _{falling below a defined distance (Δs th} ) or a defined period of time (Δt _th ) to the stop point, the power of the heating device (1) being reduced in such a way that the power with decreasing distance (Δs) or time duration (Δt) decreases until the stop point, and the stop point is estimated by means of a route destination estimator. Procedure according to Claim 1 wherein the heating device (1) is an electrically operated heating device (1). Procedure according to Claim 2 , wherein the heating device (1) is a seat heater, a window heater, an exterior mirror heater or a steering wheel heater. 4. The method according to any one of the preceding claims, wherein when reaching or falling below the defined distance (Δs _th ) or defined period of time (Δt _th ) the charging power of an electrical energy store of the motor vehicle is increased. 5. The method according to any one of the preceding claims, wherein the distance (Δs) or duration (Δt) is determined by means of a satellite-based navigation system (4). 6. Device for setting the power of a heating device (1) of a motor vehicle, comprising - means for determining the distance (Δs) or time (Δt) to a stop point by means of a route target estimator, and - control means for reducing the power of the heating device (1) when reaching or falling below a defined distance (Δs _th ) or a defined period of time (Δt _th ) up to the stop point, the output of the heating device (1) being reduced in such a way that the power decreases with decreasing distance (Δs) or time (Δt) to the stop point.

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