Predictive thermal management in a motor vehicle

Abstract

Predictive thermal management in a motor vehicle by controlling or regulating the coolant temperature of an engine cooling system to a predetermined coolant setpoint temperature, wherein - depending on current and future environmental data (UD), an intermediate step involves assigning the load to one of at least two predefined load requirement profiles (L1, L2, L3, L4), and - depending on the assigned load requirement profile (L1, L2, L3, L4), after selection of the load requirement profile (L1, L2, L3, L4), the coolant target temperature (TKs) is specified in such a way as to ensure an optimized operating mode of the vehicle, depending on current engine operating data, the current and / or future ambient data (UD) and / or taking into account the inertia of the engine cooling system. where at least one load requirement profile (L1, L2) aimed at efficiency-optimized operation and one load requirement profile (L4) aimed at dynamics-optimized operation are specified as load requirement profiles (L1, L2, L3, L4), in which driving comfort and dynamics are the main focus, respectively. wherein when assigning the load requirement profile (L1, L2) aimed at efficiency-optimized operation, a coolant setpoint temperature is specified which is higher than a standard coolant setpoint temperature specified by default from a characteristic map, and wherein when assigning the load requirement profile (L4) aimed at dynamically-optimized operation, a coolant setpoint temperature is specified which is lower than a standard coolant setpoint temperature specified by default from the characteristic map.

Description

[0001] The invention relates to a predictive thermal management system.

[0002] Currently, in motor vehicles, a thermal management coordinator is used to control all the components of the cooling system, particularly a map-controlled thermostat, an electric coolant pump, an electric fan, and the radiator shutter. The target coolant temperature is set based on the current load point, which is determined by the current engine speed and torque, ensuring an optimal coolant temperature for that specific time and load point. A disadvantage of such systems is that, for example, due to the cooling system's inertia, the target coolant temperature may only be reached after a certain delay, or even at a point when a different coolant temperature is already more appropriate and has been set.

[0003] German patent DE 199 53 511 A1 already describes a predictive thermal management system that takes environmental data and the inertia of the cooling system into account. This predictive thermal management system is intended to lead to an "optimized operating mode for fuel consumption, emissions, and / or comfort" of the vehicle engine. However, a specific design for this predictive thermal management system is not disclosed.

[0004] Furthermore, DE 199 51 362 A1 discloses a predictive thermal management system in which the coolant target temperature is specified based on ambient data, among other things, in such a way that the coolant target temperature is reduced to a minimum value during prolonged overrun operation and raised before reaching a suitable value in order to achieve more favorable conditions again when the engine's expected increased power output is reached.

[0005] Finally, DE 198 32 626 C1 also discloses a predictive thermal management system for a motor-driven vehicle that takes environmental data into account. The focus here is on predicting changes in altitude. Thus, before a power demand arises due to an incline, the temperature is reduced, and an increase is permitted during a decline. Additionally, the temperature is reduced again before reaching the downhill slope to increase the braking performance of the retarder's auxiliary brake. Such predictive thermal management requires significant computing power and precise knowledge of the environmental data, as it accurately determines in advance when an incline or decline will be reached. Other environmental conditions are not considered.

[0006] Furthermore, reference is made to DE 102 60 260 A1 and EP 1 461 517 B1 regarding the state of the art.

[0007] The object of the invention is to provide an improved predictive thermal management system that enables optimal thermal management for a wide variety of environmental situations with low computing power.

[0008] This problem is solved according to the invention by a predictive heat management system as described in claim 1. Advantageous further developments are described in the dependent claims.

[0009] The basic idea of ​​the invention is to provide predictive thermal management which, depending on certain (future) operating situations, leads either to an increase in efficiency or a gain in dynamics. For this purpose, the coolant temperature of an engine cooling system is controlled or regulated to a predetermined coolant setpoint temperature. This setpoint temperature is determined based on current engine operating data (such as speed or torque), current and / or future environmental data, and / or taking into account the inertia of the engine cooling system, such that an optimized (fuel consumption and / or dynamics) operating mode of the vehicle is achieved.To provide optimal thermal management with low computing power, the invention involves, in a first step, assigning the system to one of at least two predefined load requirement profiles based on at least the current and / or future environmental data. Depending on the assigned load requirement profile, the coolant setpoint temperature is then determined according to the logic associated with that profile, or a standard coolant setpoint temperature determined beforehand without considering the environmental data is modified. Thus, the environmental data does not directly influence the coolant setpoint temperature, but only indirectly, by first assigning the system to a specific load requirement profile in an intermediate step.Once a suitable load requirement profile has been selected, the coolant setpoint temperature is not determined directly based on the ambient data, but rather according to the logic for calculating the coolant setpoint temperature embedded within that load requirement profile. Advantageously, at least one load requirement profile geared towards efficiency-optimized operation and one geared towards dynamically optimized operation are specified. The efficiency-optimized load requirement profile is defined in such a way that energy-efficient operation of the vehicle is achieved, particularly through appropriate influence on thermal management. Selecting or assigning such a load requirement profile is useful, for example, in urban traffic or on long-distance journeys.In contrast, the load requirement profile geared towards dynamically optimized operation is defined in such a way that driving comfort and / or dynamics take precedence. Assigning such a load requirement profile is, for example, useful for highway driving.

[0010] Depending on the selected or assigned load requirement profile, in an advantageous embodiment of the invention, the coolant setpoint temperature to which adjustment is to be made can be specified in such a way that an efficiency-optimized or a dynamically optimized operating mode of the motor vehicle, in particular of the engine cooling system, is achieved. Within the framework of the efficiency-optimized operating mode, the coolant setpoint temperature can be specified in such a way that an increase in the efficiency of the motor vehicle with regard to energy consumption is achieved. In particular, the coolant setpoint temperature can be specified in such a way that a reduction in the coolant temperature reduction is achieved by reducing the reduction of the coolant setpoint temperature compared to a reduction in the coolant setpoint temperature requested based on other operating data of the motor vehicle. For example, if...If a reduction in coolant temperature is requested due to engine speed and load, this reduction is not fully implemented to achieve efficiency-optimized operation. This means that the reduction of the coolant target temperature is reduced, or possibly even completely prevented. Furthermore, within the framework of efficiency-optimized operation, the coolant target temperature can also be specified in such a way that a higher coolant target temperature than a predetermined or determined standard coolant target temperature is set.

[0011] In contrast, during dynamically optimized operation (based on an assignment to a corresponding load requirement profile), the coolant target temperature can be set in such a way as to achieve increased driving comfort or sufficient vehicle dynamics. In particular, the coolant target temperature can be set in such a way that a further reduction is made compared to the coolant target temperature or coolant temperature reduction requested based on other vehicle operating data. For example, if a certain reduction in coolant temperature is requested due to engine speed and load, a greater temperature reduction is implemented to achieve dynamically optimized operation than would be the case based on the other operating data.Furthermore, within the framework of dynamically optimized operation, the coolant setpoint temperature can also be specified in such a way that a lower coolant setpoint temperature is specified as the coolant setpoint temperature compared to a specified or determined standard coolant setpoint temperature.

[0012] Advantageously, a transitional load requirement profile can also be specified for a load requirement profile aimed at efficiency-optimized operation and for a load requirement profile aimed at dynamics-optimized operation, whereby an assignment to this transitional load requirement profile is made in the event of a detected or suspected future transition from a load requirement profile aimed at efficiency-optimized operation to a load requirement profile aimed at dynamics-optimized operation and / or in the event of a detected or suspected future transition from a load requirement profile aimed at dynamics-optimized operation to a load requirement profile aimed at efficiency-optimized operation.By assigning a vehicle to such a transitional load requirement profile, those operating states of the vehicle can be covered in which a transition from an efficiency-optimized operating mode to a dynamics-optimized operating mode or vice versa can be observed.

[0013] If, based on the recorded and evaluated environmental data and / or other monitored and evaluated operating data, an assignment to a transitional load requirement profile is made, the coolant setpoint temperature is specified in such a way that a predictive temperature adjustment of the coolant temperature to the subsequent load requirement profile is achieved. In particular, when assigning a system to a transitional load requirement profile from an efficiency-optimized operating mode to a dynamic-optimized operating mode, the coolant setpoint temperature is specified in such a way that a (further) reduction of the coolant temperature is already carried out during this transitional load requirement profile, so that a low coolant temperature is present at the time of the dynamic requirement or the dynamic-optimized operating mode.Similarly, when assigning a transitional load requirement profile from a load requirement profile aimed at dynamically optimized operation to a load requirement profile aimed at efficiency-optimized operation, a reduction in the coolant temperature setpoint temperature can be made, or even an increase in the coolant setpoint temperature can be permitted.

[0014] To assign a vehicle to one of the predefined load requirement profiles, various data points must be evaluated, as mentioned earlier. In addition to the existing current vehicle and engine data and fluid temperatures, environmental data must be considered to ensure a clear assignment to a load requirement profile focused on efficiency-optimized operation, a load requirement profile focused on dynamic operation, and / or a transitional load requirement profile. This environmental data can include, for example, map data from a navigation system, particularly route type data. For instance, the vehicle's known position and the map data stored in the navigation system can determine whether the vehicle is located within a city, on a rural road, or on a highway.Similarly, map data and a known route can be used to determine when the driver, for example, enters a highway. This data allows for a simple and quick assignment to a defined load requirement profile. Additionally, current or expected future speed data can be evaluated and considered when assigning the driver to a defined load requirement profile. This future speed data can, in turn, be determined based on speed data or route type data stored in the navigation system. For example, if the route indicates that the driver is leaving a town, it can be assumed that the speed will increase upon reaching the town's edge. If no route is known (e.g., due to missing input from the driver), the route, or the most likely route, can be determined based on other data, such as...The time of travel, traffic data, etc., are determined and evaluated for route assignment. A self-learning knowledge base can also be accessed for route determination.

[0015] The invention will be explained in more detail using the following figure descriptions. These will show Fig. 1. the interaction of all necessary components for proactive heat management, and Fig. 2 an exemplary implementation for proactive heat management.

[0016] The Fig. Figure 1 shows a navigation system (NAVI) connected to an engine control unit (DME) via a CAN bus. The DME receives all relevant environmental data (UD) for predictive thermal management from the navigation system, such as current and future possible route and road type data, or speed information stored based on the road types driven. The DME also has access to various operating data (BD1, BD2, and BD3) from the vehicle, which are evaluated for predictive thermal management. This operating data (BD1, BD2, and BD3) can include, for example, the engine speed and / or torque (i.e., the current load point), and / or the current temperatures of the coolant and the ambient / intake air. In addition to this operating data, information about the driver type may also be available.

[0017] All the aforementioned data BD1, BD2, BD3, and UD are fed within the engine control unit (DME) to a thermal management coordinator (WMK). Based on this data, the WMK performs predictive thermal management by controlling all components of the engine cooling system (MKS), in particular a map-controlled thermostat, an electric coolant pump, an electric fan, and the vehicle's radiator shutter. Specifically, depending on the available data BD1, BD2, BD3, and UD, an assignment to a predefined load requirement profile is made, and the coolant target temperature is set and regulated according to this load requirement profile.

[0018] The assignment to one of the predefined load requirement profiles, as well as the corresponding coolant target temperature specification, are now determined based on the Fig.Section 2 explains this in more detail. As mentioned above, various input variables are evaluated as part of predictive thermal management. Regarding the specification of the coolant target temperature, in addition to environmental data—in this case, route type data and an expected speed derived from the environmental data—driver type data and current vehicle operating data are evaluated. The environmental data allows for a prediction of the route and thus a prediction of the thermal management requirements. The driver type data reveals, for example, whether the driver's driving style is generally efficient or dynamic. This data can be derived from the available data of a Dynamic Stability Control (DSC) system and / or based on the number and types of gear changes or a driving mode selected by the driver (sport, eco).The operating data of the motor vehicle can – as is known from the state of the art – include the current speed and / or torque of the engine and / or the current coolant temperature.

[0019] Depending on this data, the vehicle is assigned to one of four predefined load requirement profiles: "Efficiency City" (L1), "Efficiency Rural" (L2), "Transition" (L3), and "Dynamic Level" (L4). For example, the vehicle is assigned to the "Efficiency City" load requirement profile if the environmental data indicates that it is located within a city or town, i.e., on roads with a maximum speed of 60 km / h. Similarly, the vehicle is assigned to the "Efficiency Rural" load requirement profile if the environmental data indicates that it is located outside a city or town, but not on a motorway, i.e., on roads with a speed limit between 60 and 100 km / h.

[0020] An assignment to the "Dynamic Level" load requirement profile occurs, for example, when a sporty driving style is detected and when environmental data indicates that the vehicle is on a highway and a temporary speed reduction (e.g., due to roadworks or following traffic) is imminent. Similarly, a switch from the "Efficiency City" or "Efficiency Highway" load requirement profile to the "Dynamic Level" load requirement profile occurs, for example, when an exit condition is met due to a driver-initiated "kick-down." An assignment to the "Transition" load requirement profile occurs, for example, before a town exit or highway entrance detected based on environmental data.

[0021] Depending on the assigned load requirement profile, the coolant target temperature is influenced differently. In principle, as with the state of the art, the coolant target temperature is set based on the engine operating data (speed and torque) and the driver type, such that a relatively high coolant target temperature is set at low speeds and low engine torque, and a lower coolant target temperature is set at high speeds and high engine torque. This "standard setting" can, for example, be stored in a map. Further influencing factors, such as the detection of a cold start or the exceeding of predefined temperature limits (e.g., coolant, oil, ambient / outside temperature), can also be incorporated into the standard coolant target temperature setting.

[0022] If the vehicle is assigned to the "Efficiency City" performance profile, the coolant target temperature is set, or the standard coolant target temperature specified in the characteristic map is modified or influenced, in such a way that increased efficiency is achieved by reducing the temperature drop. This means that a higher coolant target temperature is specified compared to the standard coolant target temperature. Specifically, if the standard coolant target temperature is reduced, only a smaller reduction is specified, resulting in lower power losses and increased efficiency. The extent of the reduction in coolant temperature can be derived, for example, from the vehicle's current operating data, particularly the current coolant temperature and driver type data.

[0023] Similar to the "Efficiency City" performance requirement profile, the "Efficiency Highway" performance requirement profile also achieves increased efficiency by reducing the temperature drop. However, unlike the "Efficiency City" profile, only significant coolant temperature reductions are reduced here. The extent of the coolant temperature reduction can also be derived, for example, from the vehicle's current operating data, particularly the current coolant temperature and driver type data.

[0024] If an assignment to the performance requirement profile "Dynamic Stage" has been made, the coolant target temperature is specified in such a way, or the standard coolant target temperature specified by the characteristic map is changed or influenced in such a way that an increase in dynamics is achieved through an adaptive coolant temperature reduction, i.e., instead of a coolant target temperature or cooling capacity stage determined from the characteristic map, a higher cooling capacity stage and thus a lower target temperature is specified.

[0025] If the vehicle is assigned to the "Transition" performance profile, the coolant target temperature is set, or the standard coolant target temperature specified in the engine map is modified or influenced, to achieve predictive coolant temperature adjustment. Since this performance profile is intended for vehicle operating modes where high power demand is anticipated, such as when leaving a town or highway, the coolant target temperature is proactively reduced to ensure sufficient engine cooling at the time of high power demand. The extent and timing of this coolant temperature reduction can be further customized based on the detected driver type and the vehicle's current operating data.

[0026] The thermal management system according to the invention, taking into account the low computing power of the thermal management coordinator, ensures that the engine cooling system reacts early to future operating conditions and that only the cooling necessary for the respective operating conditions is carried out, thus minimizing energy consumption.

Claims

[1] Predictive thermal management in a motor vehicle by controlling or regulating the coolant temperature of an engine cooling system to a predetermined coolant setpoint temperature, wherein - depending on current and future environmental data (UD), an intermediate step involves assigning the load to one of at least two predefined load requirement profiles (L1, L2, L3, L4), and - depending on the assigned load requirement profile (L1, L2, L3, L4), after selection of the load requirement profile (L1, L2, L3, L4), the coolant target temperature (TKs) is specified in such a way as to ensure an optimized operating mode of the vehicle, depending on current engine operating data, the current and / or future ambient data (UD) and / or taking into account the inertia of the engine cooling system. where at least one load requirement profile (L1, L2) aimed at efficiency-optimized operation and one load requirement profile (L4) aimed at dynamics-optimized operation are specified as load requirement profiles (L1, L2, L3, L4), in which driving comfort and dynamics are the main focus, respectively. wherein when assigning the load requirement profile (L1, L2) aimed at efficiency-optimized operation, a coolant setpoint temperature is specified which is higher than a standard coolant setpoint temperature specified by default from a characteristic map, and wherein when assigning the load requirement profile (L4) aimed at dynamically-optimized operation, a coolant setpoint temperature is specified which is lower than a standard coolant setpoint temperature specified by default from the characteristic map. [2] Predictive heat management according to claim 1, characterized by, that in addition to a load requirement profile (L1, L2) aimed at efficiency-optimized operation and a load requirement profile (L4) aimed at dynamics-optimized operation, a transitional load requirement profile (L3) is specified as a load requirement profile and an assignment to this load requirement profile (L3) is made in the event of a detected or suspected future transition from a load requirement profile (L1, L2) aimed at efficiency-optimized operation to a load requirement profile (L4) aimed at dynamics-optimized operation and / or in the event of a detected or suspected future transition from a load requirement profile (L4) aimed at dynamics-optimized operation to a load requirement profile (L1, L2) aimed at efficiency-optimized operation. [3] Predictive thermal management according to claim 2, characterized by, that the coolant setpoint temperature (TKs) is specified when assigning to a transitional load requirement profile (L3) from a load requirement profile (L1, L2) aimed at efficiency-optimized operation to a load requirement profile (L4) aimed at dynamically-optimized operation in such a way that a predictive temperature adjustment of the coolant temperature to the following load requirement profile (L4) is achieved. [4] Predictive thermal management according to one of the preceding claims, characterized by , that the environmental data (UD) includes data from a navigation system (NAVI), in particular route type data from a navigation system (NAVI). [5] Predictive thermal management according to any of the preceding claims, characterized by, that an assignment to a given load requirement profile (L1, L2, L3, L4) is additionally carried out taking into account given or determined expected future speed data of the motor vehicle. [6] Predictive heat management according to claim 5, characterized by that future speed data will be determined based on speed data stored in the navigation system (NAVI).

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