GB2510597A

GB2510597A - Starting an engine in dependence on cabin temperature

Info

Publication number: GB2510597A
Application number: GB1302245.4A
Authority: GB
Inventors: Marleen Thompson; Dennis Letang
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2013-02-07
Filing date: 2013-02-07
Publication date: 2014-08-13
Also published as: GB201302245D0

Abstract

A method, for operating a utility vehicle having a drivers cab and a combustion engine for driving the utility vehicle, comprising detecting a first temperature prevailing in the driver's cab S1, comparing the first temperature with a predetermined set temperature S2 and determining a second temperature prevailing in the ambience of the vehicle S4. If the first temperature S1 differs from the set temperature S2 the combustion engine is started by using energy provided by the running combustion engine at least indirectly to decrease the difference between the first temperature D1 and the set temperature S2. The engine is stated if the first temperature S1 is equal to or above the second temperature S2 and the engine may be kept running for predetermined period of time, e.g. 5 minutes. Second temperature S2 may be determined by a sensor or calculated or received by some other means. Reference is also made to a utility vehicle having a control unit which carries out the method.

Description

Method for Operating a Utility Vehicle and Utility Vehicle The invention relates to a method for operating a utility vehicle and to a utility vehicle.

A method for reducing starts during automated start-up arid.stopcontrol responsive to battery voltage detection can be found in US 7,036,477 B1. In said method a runtime is extended after a start-up command is generated. Said start-up command is generated by sensing a time interval between a stop engine command and a subsequent start engine command by determining when said interval is less than a start-up time threshold selected as representative of chargeability and by generating an extended run command enabling said stop command to be delayed to an extended time beyond a preselected restart battery time. * *

US 7,146959 B2 discloses a method for adjusting an automated start and stop control having a mode selecting an engine start in response to detection of a battery voltage corresponding to a low battery voltage threshold, the method comprising adjusting the low * ** battery start-up threshold limit as a function of ambient air temperature by sensing an ::: ambient temperature, by comparing said temperature with a corresponding reference memory and by updating said low battery start-up limit at a memory location.

Moreover, a method for reducing idle operation of a prolonged period of automated start and stop control responsive to ambient temperature or battery conditions by a thermostat mode control can be found in US 7,003,395 Bi. In said method the thermostat mode operation is limited to a predetermined time limit by setting a programmable time limit value, by sensing once the time limit has expired during operation of said automated -control and by disabling response to requests for start-up from the thermostat mode control after said sensing has detected expiration and said automated control remains active.

Furthermore, US 7091629 B2 discloses a method for automatically starting and stopping an internal combustion engine installed in a vehicle having an electronic engine control system in communication with a starter motor and a plurality of fuel injectors, the method comprising determining in any sequence that one of the following three conditions exists: a voltage of a battery is below a predetermined limit, a temperature of the engine is below a predetermined limit, or a temperature of a cab of the vehicle is outside of a predetermined temperature range. Once a positive indication of one of said conditions exists it is confirmed that a hood is closed, that a transmission is neutral, and that a park brake is set. Finally, the engine is started.

In IDE 102011102 327 Al an engine system can be found, the engine system comprising a stop-start-module which generates a shut down signal for shutting down an engine. The enginesystem further comprisesa friction modulewhich generates a friction signal on the basis of said shut down signal. The friction signal indicates an estimated value of an amount of friction forces between components of the engine. The engine system also comprises a position module which estimates a position of the engine and which generates a position signal.

Moreover, the engine system comprises an energy module which estimates the kinetic energy of the engine on the basis of the friction signal and of the position signal.

*" Furthermore, the engine system comprises a cylinder shut down module which stops the engine in a predetermined position and/or in a predetermined portion on the basis of the *. .: kinetic energy.

* From IDE 102001 006 854 Al a method for operating a vehicle engine coupled to a :.: transmission is known, the method comprising fixing the transmission to a framework of the vehicle during a stopped status of the vehicle. In said method the power of the engine is increased while the transmission is fixed in order to generate increased waste heat of the engine.

Moreover, it is known from the general prior art to run combustion engines of heavy-duty vehicles at Idle in order to heat or cool an interior of a driver's cab of the respective vehicle. This can result in very high greenhouse gas emissions. -It is therefore an object of the present invention to provide a method for operating a utility vehicle and to provide a utility vehicle which allow for a very comfortable temperature control of an interior of the vehicle.

This object is achieved by a method for operating a utility vehicle having the features of patent claim 1 and by a utility vehicle having the features of patent claim 8. Advantageous embodiments with expedient and non-trivial developments of the invention are indicated in the other patent claims.

A first aspect of the invention relates to a method for operating a utility vehicle having a driver's cab and a combustion engine for driving the utility vehicle. In said method a first temperature prevailing in the driver's cab is detected. Further, said first temperature is compared with a predeterminable set temperature. For example, the set temperature can be predetermined by the driver of the utility vehicle by entering a desired temperature into an operating system of the vehicle. In said method, a second temperature prevailing in the ambient, i.e. in the surroundings of said utility vehicle is determined. Said second temperature is also referred to as ambient temperature.

If said first temperature differs from said set temperature, said combustion engine is started and energy providing by said running combustion engine is used at least indirectly to decrease the difference between said first temperature and said set temperature. In other words, by using the energy provided by the running combustion engine an interior of * the driver's cab is, for example, cooled or heated. For example, for heating the driver's * cab waste heat of the running combustion engine can be used at least indirectly. * .

In the method of the present invention, the ambient temperature is taken into consideration when controlling the first temperature prevailing in the driver's cab. In doing so, the first temperature can be controlled in a very efficient way with very low :: * greenhouse gas emissions. Moreover, the first temperature can be adjusted to the set temperature desired, for example, by the driver so that very comfortable conditions can be generated in the driver's cab.

The method of the present invention can be, for example, conducted by a control logic of the combustion engine and/or of the utility vehicle, the control logic, for example, being implemented via a controller based on data stored ma computer-readable storage media, for example, in addition to various other electric and electronic circuits and/or hardware.

As will be appreciated by persons skilled in the art, the control logic may be implemented or effected in hardware, software, or a combination of hardware and software. The various functions are preferably effected by a programmed micro processor, such as included in a DDEC controller by Detroit Diesel Corporation, Detroit, Michigan.

Of course, control of the combustion engine and/or of the vehicle may include one or more functions implemented by dedicated electric, electronic or integrated circuits. As will also be appreciated by persons skilled in the art, the control logic may be implemented using any of the number of known programming and processing techniques or strategies.

In the method of the present invention measurements of the ambient air temperature as a criterion for starting the combustion engine, for example, while operating in a cab thermostat mode, is included. In said cab thermostat mode, the first temperature prevailing in the driver's cab is controlled and preferably adjusted to the set temperature.

For example, if energy provided by the running combustion engine is required tp decrease the diffeience between said first temperature and said set temperature, the combustion engine is started in dependency on said second temperature and if said first temperature differs from said set temperature and the ambient temperature is extreme.

In a very advantageous embodiment of the present invention, said combustion engine is started if said second temperature is below or equal to a first threshold value or if said * * second temperature is above or equal to a second threshold value. Preferably, the first threshold value is 30°F and the second threshold value is 90°F. By monitoring the ambient air temperature conditions and determining, for example, within the control logic, if the ambient air temperature is extreme, i.e. said second temperature is below or equal to said first threshold value or above or equal to said second threshold value, an : optimized idle cab thermostat mode can be realized, the optimized idle cab thermostat :: * mode providing a very high comfort for the driver with very low greenhouse gas emissions. This is particularly beneficial if the combustion engine is configured as a heavy-duty diesel engine whose greenhouse gas emissions can be kept to a minimum by means of said method.

In a further embodiment of the present invention said combustion engine is kept running for a predetermined period of time and is shut down after said period of time if said second temperature exceeds said first threshold value or if said second temperature drops below said second threshold value. Thereby, the energy provided by the running combustion engine can be used to control the temperature prevailing the driver's cab during said period of time, Furthermore, greenhouse gas emissions can be kept particularly low.

It has turned out to be particularly advantageous if said period of time is five minutes. It has shown that live minutes is enough time to realise a very comfortable temperature prevailing in the driver's cab while keeping the emissions of the combustion engine particularly low.

For determining said second temperature very precisely, in a particularly advantageous embodiment of the present invention said second temperature is determined by capturing said second temperature by means of at least one temperature sensor. Said temperature sensor may be attached to the driver's cab or to a framework of the utility vehicle and may be arranged at least partially at the outside of the driver's cab.

Advantageously, said second temperature is determined by calculating said second temperature in dependency of a calculation model by means of a control unit of the utility vehicle. Thereby, the second temperature can be determined in a very cost-efficient way.

In a further particularly advantageous embodiment of the present invention said second temperature is determined by receiving said second temperature from at least one means being separate and different from the utility vehicle. In this connection the second temperature, for example, can be received by means such as but not limited to at least ** one other vehicle via a wireless communication system and/or by a stationary device via a wireless communication system. Hereby, a very precise and cost-efficient determining of * the second temperature can be realized.

* A second aspect of the present invention relates to a utility vehicle having a driver's cab, a :: f combustion engine for driving the utility vehicle and at least one control unit for controlling at least the combustion engine, the control unit being configured to execute the method of the first aspect of the present invention. This means that the control unit is configured to detect a first temperature prevailing in the driver's cab, to compare said first temperature with a predeterminable set temperature, to determine a second temperature prevailing in the ambiance of said utility vehicle and to start said combustion engine and to use energy provided by said running combustion engine at least indirectly to decrease a difference between said first temperature and said set temperature in dependency on said second temperature and if said first temperature differs from said set temperature. Advantageous embodiments of the first aspect of the invention are to be regarded as advantageous embodiments of the second aspect of the present invention and vice versa.

Thus, the driver's cab of the utility vehicle can be cooled and, in particular, heated in a very efficient way with very low greenhouse gas emissions. Moreover, the temperature prevailing in the driver's cab can be adjusted to the set temperature, for example, desired by the driver so that very comfortable conditions prevailing in the driver's cab can be generated.

Further advantageous, features and details of the invention derive from the following description of a preferred embodiment and from the drawing. The features and feature combinations set out in the description and the features and feature combinations set out in the description of the figures and/or displayed alone in the figures below can be used not only in the respectively indicated combination but also in other combinations or alone without leaving the scope of the invention.

The drawing shows in: Fig 1 a flow chart for illustrating a method for operating a utility vehicle having a driver's cab and a combustion engine for driving the utility vehicle, wherein said combustion engine is started and stopped in dependency on a temperature prevailing in the ambience of said utility vehicle, and wherein energy provided by said running combustion engine is used at least indirectly to control a temperature prevailing in said driver's cab; and S. S Fig. 2 a further flow chart for illustrating a part of said method illustrated by fig. 1.

Fig. 1 shows a flow chart 10 for illustrating a method for operating a utility vehicle having a driver's cab and a combustion engine for driving the utility vehicle. The combustion * " engine, for example, is configured as a heavy-duty diesel motor operated by liquid fuel in the form of diesel.

In a first step Si of said method a first temperature prevailing in the driver's cab is detected. Said first temperature is also referred to as interior temperature. In a second step S2 of said method the interior temperature (first temperature) is compared with a predeterminable set temperature. Said set temperature, for example, is a temperature desired to be prevailing in the driver's cab by the driver. The set temperature, for example, can be set by the driver by entering the set temperature into an operating system of the utility vehicle via operating means. If the first temperature prevailing in the driver's cab (interior temperature) does not differ from said set temperature or a difference between the interior temperature and the set temperature is lower than a predeterminable threshold the first step Si follows the second step S2. This means that the interior temperature prevailing in the driver's cab is satisfied, If the first temperature differs from the set temperature and/or the difference between the interior temperature and the set temperature is equal or higher than the predeterminable threshold a third step 83 of said method follows the second step 82. Moreover, in a fourth step S4 of said method a second temperature prevailing in the ambiance of said utility vehicle is determined. Said second temperature is also referred to as ambient temperature. The ambient temperature can be determined by detecting the ambient temperature by means of at least one sensor which is at least partially arranged outside the driver's cab. The ambient temperature can also be calculated by a control unit of the utility vehicle in dependency of a calculation model. Moreover, the ambient temperature can be received by means such as but not limited to other vehicles and/or other communication systems, for example, via a wireless communication network.

In the third step 83 the ambient temperature is compared with a first threshold value and * . with a second threshold value. The first threshold value is 30 °F and the second threshold *r": value is 90 °P. If the ambient temperature is below or equal to the first threshold value the ambient temperature is considered to be extreme. Further, if the ambient temperature is equal to or above the second threshold value, the ambient temperature is also considered to be extreme. * ** * *

:: * If the ambient temperature is not considered to be extreme in the third step S3 the first step Si follows the third step S3. If, in the third step S3, the ambient temperature is considered to be extreme, a fifth step S5 of said method follows the third step S3. In the fifth step S5 a cab thermostat mode is allowed. In other words, in the fifth step 85 a cab thermostat mode is executed. In said cab thermostat mode, i.e. in the fifth step S5 the combustion engine which has been shut down or deactivated so far is started and energy provided by the started and running combustion engine is used at least indirectly to decrease the difference between the set temperature and the interior temperature. This means that in the fifth step S5 the energy provided by the running combustion engine is used to cool or to heat the driver's cab in order to adjust the interior temperature to the predeterminable set temperature desired by the driver.

By considering the ambient temperature and by considering if the ambient temperature meets said definition of extreme ambient temperature when starting the combustion engine in the cab thermostat mode, the interior temperature can be controlled in a very efficient way and with very low greenhouse gas emissions. Furthermore, a very high comfort for the driver can be realized because the interior temperature is adjusted to the set temperature automatically.

Fig. 2 shows a further flow chart 12 illustrating a part of the method illustrated by fig. 1. In a sixth step S6 of said method it is checked whether the cab thermostat mode executed or started in the fifth step Sb is running. If so, in a seventh step S7 following the sixth step S6 it is checked whether the ambient temperature is considered to be extreme or not.

This means that in the seventh step 87 the ambient temperature is compared with the first threshold value and with the second threshold value.

If the ambient temperature is considered to be extreme, the sixth step 86 follows the seventh step 57. If the ambient temperature is not considered to be extreme, an eighth step 58 of said method follows the seventh step 57. In the eighth step S8 the running combustion engine is stopped after a time period of five minutes. In other words, in the eighth step SB the combustion engine is kept running for a predetermined period of time * * and the combustion engine is shut down, i.e. stopped after said period of time if the * ambient temperature (second temperature) exceeds the first threshold value or if the ambient temperature drops below the second threshold value, wherein said period of time * is five minutes. In doing so, the greenhouse gas emissions can be kept to a minimum and the difference between the set temperature and the interior temperature can be also kept to a minimum, If the engine has been running five minutes, then the engine is shut down ::.: (58). Otherwise the engine continues running (56).

Claims

Claims A method for operating a utility vehicle having a driver's cab and a combustion engine for driving the utility vehicle, the method comprising: -detecting a first temperature prevailing in the driver's cab (Si); * * -comparing said first temperature with a predeterminable set temperature (S2); -determining a second temperature prevailing in the ambience of said utility vehicle (S4); and -if said first temperature differs from said set temperature: starting said combustion engine and using energy provided by said running combustion engine at least indirectly to decrease the difference between said first temperature and said set temperature (S5).
2. The method according to claim 1, characterized in that said combustion engine is started if said second temperature is below or equal to a first threshold value, in particular 30 degrees Fahrenheit, or if said second temperature is above or equal to a second threshold value, in particular 90 degrees Fahrenheit (S5).
3. The method according to claim 2, characterized in that said combustion engine is kept running for a predeterminable period of time and is shut down after said period of time if said second temperature exceeds said first threshold value or if said second temperature drops below said second threshold value (58).
4. The method according to claim 3.characterized in that said period of time is five minutes.
5. The method according to any one of the preceding claims, characterized in that said second temperature is determined by capturing said second temperature by means of at least one temperature sensor:
6. The method according to any one of the preceding claims, characterized in that said second temperature is determined by calculating said second temperature in dependency of a calculation model by means of a control unit of the utility vehicle.
7. The method according to any one of the preceding claims, characterized in that said second temperature is determined by receiving said second temperature from at least one means being separate and different from the utility vehicle. * 0s I. S:
8. A utility vehicle having a driver's cab, a combustion engine for driving the utility . . vehicle and at least one control unit for controlling at least the combustion engine, the control unit being configured to: -detect a first temperature prevailing in the driver's cab (Si); -compare said first temperature with a predeterminable set temperature (S2); -determine a second temperature prevailing in the ambience of said utility vehicle (S4); and -if said first temperature differs from said set temperature: start said combustion engine and to use energy provided by said running combustion at least indirectly to decrease the difference between said first temperature and said set temperature (S5).