VEHICLE DISPLAY DEVICE

Abstract

Vehicle display device for an electric vehicle (10) with a friction brake (31), wherein the vehicle display device (11) comprises the following: - a loss energy calculation module (62) that calculates a loss energy released by the electric vehicle (10) on the basis of an actuation state of the friction brake (31), where, when calculating the energy loss, a regenerative moment is subtracted from a total braking torque, wherein the regenerative torque is a torque generated by an electric motor (13) of the electric vehicle during regenerative braking and the total braking torque is a braking torque required for a vehicle braking operation of the electric vehicle (10); - an electrical energy calculation module (61) that calculates electrical energy consumed or generated by the electric vehicle (10) on the basis of a charging / discharging power of an electrical storage device (24) present in the electric vehicle (10); - a consumption calculation module (63) that calculates the energy consumption consumed by the electric vehicle (10) on the basis of the energy loss and the electrical energy; - a first efficiency calculation module (67) that calculates an initial energy efficiency based on a driving distance and energy consumption over a first period of time; - a second efficiency calculation module (68) that calculates a second energy efficiency based on a distance traveled and energy consumption over a second period of time that is shorter than the first period of time; and - a display control module (70) that controls the display content of an onboard display device (41) based on an efficiency difference between the first energy efficiency and the second energy efficiency.

Description

BACKGROUND 1. Technical field

[0001] The present invention relates to a display device for vehicles, in particular to a display device intended for an electric vehicle with a friction brake. 2. Relevant state of the art

[0002] Electric vehicles include electric cars and fuel cell cars, which use an electric motor as their power source. Hybrid vehicles, which combine a combustion engine and an electric motor, are also considered electric vehicles. Furthermore, plug-in hybrid vehicles, which can be charged using an external power source, have been developed. A driver's driving style is important for improving both electricity costs and fuel costs for these electric vehicles.

[0003] For this reason, a display device for vehicles has been developed which shows a difference between the current instantaneous fuel costs and the average fuel costs in the past on a display instrument and encourages a driver to drive appropriately (see unexamined Japanese patent application publication JP 2014-118 816 A).

[0004] The vehicle display device disclosed in JP 2014-118 816 A shows the difference between current fuel costs and average fuel costs. Thus, it continuously displays excellent fuel costs during electric motor operation and during braking, when the internal combustion engine is off. However, to improve the energy efficiency of an electric vehicle, such as reducing electricity costs and fuel costs, it is important to encourage the driver to adopt a driving style that also contributes to improved energy efficiency during electric motor operation and braking.

[0005] DE 10 2013 225 070 A1 describes a display device for a vehicle, which is provided in a vehicle with an idle-stop function and comprises the following: a fuel efficiency meter for displaying fuel efficiency information about the vehicle, a unit for calculating an average fuel efficiency based on a distance traveled within a first period and fuel consumption within the first period, and a unit for calculating an instantaneous fuel efficiency based on a distance traveled within a second period, which is shorter than the first period, and fuel consumption within the second period.The device also includes a fuel efficiency difference calculation unit and a specification value setting unit for controlling the fuel efficiency gauge display based on a fuel efficiency difference between the average fuel efficiency and the instantaneous fuel efficiency. When the instantaneous fuel efficiency reaches a reference value, before switching to an idle-stop state, the fuel efficiency difference calculation unit and the specification value setting unit control the fuel efficiency gauge based on the last fuel efficiency difference, without updating the fuel efficiency difference.

[0006] DE 10 2009 019 810 A1 describes a method for determining the instantaneous fuel consumption of a vehicle that has at least one drive motor and at least one energy storage device in which energy for operating the drive motor can be stored. A change in the energy stored in the at least one energy storage device, as well as a change in the kinetic energy and / or a change in the potential energy of the vehicle, are combined to determine the instantaneous fuel consumption.

[0007] US Patent 2009 / 0251303A1 describes a vehicle display device and an idle stop function that automatically stops the engine when the vehicle temporarily comes to a standstill. The display device includes a control unit that calculates the deviation of the current, instantaneous fuel consumption from the average fuel consumption over a predetermined period. A fuel consumption display shows fuel consumption information indicating whether the current driving condition of the vehicle reduces the average fuel consumption. When the vehicle is in the idle stop condition, the fuel consumption display indicates that the deviation is zero, regardless of the instantaneous fuel consumption or the average fuel consumption.

[0008] German patent application DE 11 2010 000 712 T5 describes an information display system and a method for displaying the energy efficiency of a vehicle. The vehicle may include an energy source that supplies energy to the electric machine. The information display system may include an information display configured to show an efficiency indicator, which in turn is configured to display the vehicle's efficiency. The controller is further configured to determine an energy efficiency value based on information from the braking system. The controller may also be configured to transmit the energy efficiency value so that the information display shows the efficiency indicator based on this value.

[0009] German patent DE 10 2007 016 615 A1 describes a display device for vehicles that can display a vehicle's fuel consumption information in a useful and optimal manner for the driver. An instrument control device calculates the instantaneous fuel consumption of a vehicle based on the distance traveled and the amount of fuel injected within a predetermined time period, calculates the average fuel consumption of the vehicle based on the respective cumulative values ​​of the distance traveled and the amount of fuel injected, which are repeatedly calculated for each predetermined time period, and displays the deviation of the instantaneous fuel consumption from the average fuel consumption as fuel consumption information on a fuel consumption gauge. The display process on the fuel consumption gauge is carried out by pivoting a pointer relative to a neutral position.If the deviation takes on a positive value, the pointer is pivoted in the direction of the impulse with a deflection width corresponding to the amount of the deviation, while if the deviation takes on a negative value, the pointer is pivoted in the negative direction with a deflection width corresponding to the amount of the deviation.

[0010] US 2014 / 0200793A1 describes a method and system for determining and displaying a rate corresponding to the distance traveled by a vehicle per unit of fuel equivalent energy consumption, and specifically for determining and displaying the number of miles or kilometers traveled per gallon or liter of total fuel and fuel equivalent non-fuel energy consumed. The system includes an electronic control unit, a motor, a fuel control unit, a battery, a battery management and control unit, and a display. The method and system determine the total fuel equivalent energy consumption based on a constant energy conversion factor or energy conversion efficiency loss factor, which is determined in real time.The procedure and the system also determine and display the fuel equivalent cost for each kilometer or mile traveled. The procedure and the system also adjust the vehicle's operation based on the calculated rate and fuel equivalent cost. BRIEF DESCRIPTION OF THE INVENTION

[0011] One objective of the present invention is to encourage a driver to adopt a driving style that contributes to improved energy efficiency.

[0012] The problem underlying the invention is solved by a vehicle display device with the features of independent claim 1.

[0013] Further developments of the vehicle display device according to the present invention are specified in dependent claims 2 to 7. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings show: Fig. 1 a schematic representation of an exemplary configuration of a hybrid vehicle; Fig. 2 a schematic representation of an example of a vehicle display device; Fig. 3A to 3D representations of display situations of an ECO or eco display; Fig. 4. A block diagram to illustrate an example of a function of an instrument control unit; and Fig. 5 A conceptual representation to illustrate an example of the display behavior of an ECO display. DETAILED DESCRIPTION

[0015] A preferred embodiment of the present invention is described in detail below with reference to the accompanying drawings. It should be noted that in this description and the accompanying drawings, structural elements that have essentially the same function and structure are designated by the same reference numerals, and a repeated explanation of these structural elements is omitted.

[0016] The embodiment of the present invention is described in detail below with reference to the drawings. Fig. Figure 1 shows a schematic representation of an exemplary configuration of a hybrid vehicle (electric vehicle). 10. The in Fig. The hybrid vehicle 10 shown in Figure 1 is equipped with a vehicle display device 11, which is an embodiment of the present invention.

[0017] As in Fig. As shown in Figure 1, the hybrid vehicle 10 is equipped with a drive unit 14 comprising an internal combustion engine 12 and a motor / generator 13, which serve as drive sources. This drive unit 14 is equipped with a continuously variable transmission 17, which has a primary disc 15 and a secondary disc 16.

[0018] The internal combustion engine 12 is coupled to one side of the primary disc 15 via a clutch 18, and the motor / generator 13 is coupled to the other side of the primary disc 15. Wheels 21 are coupled to the secondary disc 16 via an output shaft 19, a differential mechanism 20, and the like. Furthermore, a battery 24 is connected to a stator 22 of the motor / generator 13 via an inverter 23.

[0019] The hybrid vehicle 10 is equipped with a regenerative brake 30 and a friction brake 31, which serve as a braking system for braking the wheels 21. The regenerative brake 30 comprises the motor / generator (electric motor) 13, which is mechanically connected to the wheels 21, and the battery (electrical storage device) 24, which is electrically connected to the motor / generator 13. When the regenerative brake 30 is activated, the motor / generator 13 is switched to a power generation state.

[0020] Thus, the motor / generator 13 can generate braking power to brake the wheels 21. This regenerative braking 30 converts the kinetic energy of the hybrid vehicle 10 into electrical energy and collects or stores the electrical energy by causing the motor / generator 13 to recover energy and charge the battery 24.

[0021] The friction brake 31 has a master cylinder 33, which generates hydraulic brake pressure in conjunction with a brake pedal 32, and a brake caliper 35, which brakes a disc rotor 34 of a respective wheel 21 by means of the hydraulic brake pressure from the master cylinder 33. The friction brake 31 also has a hydraulic unit 36, which includes an electric pump, an accumulator, an electromagnetic valve, and the like. The hydraulic unit 36 ​​is located between the master cylinder 33 and the brake caliper 35, and the hydraulic brake pressure controlled by the hydraulic unit 36 ​​is supplied to each brake caliper 35.

[0022] When a driver presses or operates the brake pedal 32, the hydraulic brake pressure is supplied to the brake caliper 35 via the hydraulic unit 36. This presses a brake pad (not shown) of the brake caliper 35 against the disc rotor 34, and friction between the brake pad and the disc rotor 34 slows the wheel 21. In this way, the friction brake 31 converts the kinetic energy of the hybrid vehicle 10 into heat energy and releases this heat energy.

[0023] Fig. Figure 2 shows a schematic representation of an example of the vehicle display device 11. As in Fig. As shown in Figure 2, the vehicle display device 11 is equipped with a combination instrument 40 that displays various types of information to the driver. The combination instrument 40 has a display device (on-board display device) 41, such as a liquid crystal display, a speedometer 42 that shows the vehicle speed, a tachometer 43 that shows the engine speed, and the like.

[0024] As in the enlarged part of the Fig. As shown in Figure 2, an ECO indicator 44 is displayed on the display unit 41 of the instrument cluster 40. This ECO indicator 44 shows information regarding the energy efficiency level of the hybrid vehicle 10. High energy efficiency, i.e., good energy efficiency, is understood to mean low electricity and fuel consumption per unit of distance traveled, while low energy efficiency, i.e., poorer energy efficiency, is understood to mean high electricity and fuel consumption per unit of distance traveled.

[0025] The Fig. Figures 3A to 3D illustrate display situations of the ECO display 44. As in Fig. 3A and Fig. As shown in Figure 3B, when a driving style that improves energy efficiency is executed, a display bar 45 with a positive trend (+ side) is shown. As in Fig. 3C and Fig. In 3D representation, when driving in a manner that reduces energy efficiency, the indicator bar 45 is displayed with a curve towards the negative side (- side).

[0026] It should be noted that the displayed indicator bar 45 extends further towards the positive side with increasing energy efficiency, as shown in Fig. 3B is shown, and extends further towards the negative side with decreasing energy efficiency, as shown in Fig. It is displayed in 3D.

[0027] Next, a control system of the hybrid vehicle 10 is described. As in Fig. As shown in Figure 1, the hybrid vehicle 10 has a multitude of electronic control units 50 to 54. The electronic control units provided are the combustion engine control unit 50, which controls the combustion engine 12, the hybrid control unit 51, which controls the motor / generator 13 and the like, and the battery control unit 52, which controls the battery 24.

[0028] In addition, the following electronic control units are provided: the brake control unit 53, which controls the friction brake 31; the instrument control unit 54, which controls the instrument cluster 40; and the like. These electronic control units 50 to 54 comprise a microcomputer including a CPU, ROM, RAM, and the like, a control circuit that generates control current for various actuating devices, and the like.

[0029] The electronic control units 50 to 54 are interconnected via a vehicle-specific network 55, such as a CAN bus. Furthermore, the vehicle-specific network 55 receives signals from various sensors (not shown) indicating vehicle states, such as vehicle speed, combustion engine speed, (electric) motor revolutions, accelerator pedal actuation, and brake actuation.

[0030] The instrument control unit 54 contained in the vehicle display device 11 is described below. First, an overview of the control process of the ECO display 44 by the instrument control unit 54 is briefly described. The instrument control unit 54 calculates the energy efficiency of the hybrid vehicle 10 based on the distance traveled by the hybrid vehicle 10 and the energy consumed during that distance.

[0031] The instrument control unit 54 calculates energy efficiency based on an average energy efficiency over a first period and an instantaneous energy efficiency over a second period, which is shorter than the first. The instrument control unit 54 then displays the efficiency difference between the average and instantaneous energy efficiency on the ECO display 44 and encourages the driver to adopt a driving style that increases energy efficiency.

[0032] This means that if the current energy efficiency achieved through the current driving style exceeds the average energy efficiency, indicator bar 45 of the ECO display 44 will show a positive trend. If the current energy efficiency achieved through the current driving style falls below the average energy efficiency, indicator bar 45 of the ECO display 44 will show a negative trend.

[0033] In this way, the driver can recognize a driving style that contributes to improved energy efficiency by looking at the ECO display 44, and the energy efficiency of the hybrid vehicle 10 can be improved.

[0034] The following section describes in detail the control process of the ECO display 44 by the instrument control unit 54. Fig. Figure 4 shows a block diagram to illustrate an example of a function of the instrument control unit 54. As in Fig. As shown in Figure 4, the instrument control unit 54 includes a fuel energy calculation module 60. The fuel energy calculation module 60 calculates the fuel energy C consumed by the internal combustion engine 12. FkW per unit of time.

[0035] The fuel energy calculation module 60 is assigned a fuel consumption C F per unit of time supplied by the combustion engine control unit 50. As expressed by the following equation (1), the fuel energy calculation module 60 multiplies the fuel consumption C. F with an energy quantity k c2j per unit volume, to convert fuel energy C FkW to calculate, which is the amount of heat per unit of time.

[0036] In this way, the fuel energy calculation module 60 calculates the fuel energy C consumed by the hybrid vehicle 10. FkW based on fuel consumption C Fof the internal combustion engine 12. It should be mentioned that fuel consumption C F This concerns the amount of fuel injected by an injector (not shown) of the internal combustion engine 12. CFkW[kW]=CF[cm3 / s]×kc2j[kJ / cm3]

[0037] The instrument control unit 54 has an electrical energy or current energy calculation module 61. The electrical energy calculation module 61 calculates an electrical energy C. EkW per unit of time, which is mainly consumed and recovered by the motor / generator 13. The electrical energy calculation module 61 receives a charging / discharging power C from the battery control unit 52. EBat The battery receives 24 units of power per unit of time. As expressed by the following equation (2), the electrical energy calculation module 61 calculates the charging / discharging power C. EBat as electrical energy C EkW, which is a quantity of heat per unit of time.

[0038] The charging / discharging power C is used in this process. EBat It is detected as a positive value during battery discharge and as a negative value during battery charging. This means the consumed electrical energy C EkW is calculated as a positive value during battery discharge, and the recovered (i.e. generated) electrical energy C EkW is calculated as a negative value during battery charging.

[0039] In this way, the electrical energy calculation module 61 calculates the electrical energy C consumed or generated by the hybrid vehicle 10. EkW based on the charging / discharging power C EBat battery 24. CEkW[kW]=CEBat[kW]

[0040] The instrument control unit 54 has a loss energy calculation module 62. The loss energy calculation module 62 calculates a loss energy C released mainly by the friction brake 31. BkW per unit of time. The loss energy calculation module 62 receives a total braking torque T from the hybrid control unit 51. Total , a regenerative or generator moment T BR as well as the (electric) motor revolutions N supplied.

[0041] As expressed by the following equation (3), the loss energy calculation module 62 subtracts the generator moment T. BR of the total braking torque T Total and multiplies the resulting value by the engine revolutions N and a conversion factor k T2P , in order to reduce the energy loss C BkWto calculate, which is a quantity of heat per unit of time. In this way, the loss energy calculation module 62 estimates an actuation state of the friction brake 31 from the total braking torque T. Total and the generator moment T BR and calculates the energy loss C BkW based on the actuation state of the friction brake 31.

[0042] This means that the energy loss calculation module 62 calculates the energy loss C released by the hybrid vehicle 10. BkW based on the actuation state of the friction brake 31. It should be mentioned that the total braking torque T Total , which is the braking torque required by the hybrid vehicle 10 during a vehicle braking process, is specified on the basis of the vehicle speed, the extent of actuation of the brake pedal 32 and the like.

[0043] At the generator moment T BRThis refers to the generator torque produced by the motor / generator 13 during regenerative braking. The (electric) motor revolutions N indicate the rotational speed of the motor / generator 13, and the conversion factor k T2P This is a factor for converting work into heat. It should be noted that the total braking torque T is... Total and the generator moment T BR about the total braking torque and the generator torque acting on a rotor shaft 25 of the motor / generator 13. CBkW[kW]=(TTotal−TBR)[Nm]×N[min−1]×kT2P

[0044] The instrument control unit 54 has a consumption calculation module 63. The consumption calculation module 63 calculates the energy consumption C consumed by the hybrid vehicle 10. kW per unit of time. The fuel energy C is assigned to the consumption calculation module 63. FkW , the electrical energy C EkWand the energy loss C BkW supplied by energy calculation modules 60 to 62.

[0045] As expressed by the following equation (4), the consumption calculation module 63 combines the fuel energy C FkW , the electrical energy C EkW and the energy loss C BkW to calculate energy consumption C kW per unit of time. CkW[kW]=CFkW[kW]+CEkW[kW]+CBkW[kW]

[0046] This refers to energy consumption C. kW to calculate the consumption obtained by adding the energy recovered, the amount of which varies depending on braking situations, to the energy consumed by the combustion engine 12 and the motor / generator 13. In other words, at energy consumption C kW This is a consumption that can be calculated by adding the energy loss C. BkWreceives, which would have been recovered depending on braking situations, i.e. the loss energy C BkW , which is not recovered as power by the regenerative brake 30, but is released as heat by the friction brake 31.

[0047] If, during deceleration or braking of the hybrid vehicle 10, the extent of actuation of the brake pedal 32 is small or the actuation speed for actuating the brake pedal 32 is low, the proportion of the friction brake 31 to the total braking torque is reduced; thus, the energy loss C decreases. BkW off, and the energy consumption C kW becomes smaller. In other words, with a light press of the brake pedal 32, the proportion of regenerative braking 30 to the total braking torque increases; thus, the energy loss C decreases. BkW lower, and the energy consumption C kW decreases.

[0048] When the hybrid vehicle 10 decelerates, if the extent of actuation of the brake pedal 32 is high or the actuation speed of the brake pedal 32 is high, the proportion of the friction brake 31 in the total braking torque increases; thus, the energy loss C BkW higher, and the energy consumption C kW is increasing.

[0049] In other words, when the brake pedal 32 is pressed hard, the proportion of the regenerative braking 30 in the total braking torque decreases; thus, the energy loss C is reduced. BkW higher, and the energy consumption C kW increases. As described above, energy consumption C takes into account. kW the braking situations of the hybrid vehicle 10.

[0050] To calculate energy efficiency using this energy consumption C kWThe instrument control unit 54 has a distance calculation module 64 that calculates a distance V traveled per unit of time. The distance calculation module 64 receives a vehicle speed signal from the hybrid control unit 51 and calculates the distance V [km / s] per unit of time based on this signal. It should be noted that, without using a vehicle speed signal, the distance traveled can be calculated based on a position signal, such as one provided by a GPS (Global Positioning System).

[0051] The instrument control unit 54 then divides the distance traveled V by the energy consumption C. kW and calculates the energy efficiency of the hybrid vehicle 10 in the manner described above. However, the energy consumption C includes kW the electrical energy C EkW, which becomes a negative value when the battery is charged, i.e., the regenerative energy; for this reason, the energy consumption C is assumed to be kW varies above "0". A problem arises from the fact that a variation in energy efficiency occurs when calculating energy efficiency if the energy consumption C kW , which is a denominator that passes through the value "0".

[0052] Therefore, the instrument control unit 54 has an energy offset addition module 65, which reduces the energy consumption C kW to update energy consumption C kW on an energy consumption C kWO increases. As expressed by the following equation (5), the energy offset addition modulus 65, which serves as the consumption addition modulus, adds an offset value k. O , which is a first additive value, to which energy consumption C kW , to reduce the increased energy consumption CkWO to calculate.

[0053] This means the offset value k O is specified in such a way that the energy consumption C kWO retains a positive value even when the fuel energy C FkW and the energy loss C bkW has the value "0" and the electrical energy C EkW calculated as a high negative value due to a regenerative braking process. CkWO[kW]=CkW[kW]+kO

[0054] If only the energy consumption C kW (denominator) is increased, so it is assumed that the energy efficiency calculation results will differ. This means that in a situation where energy consumption C kW and as the distance traveled V approaches the value "0", energy efficiency converges to "1" when the energy consumption C kW(denominator) has not been increased. In contrast, in a situation where energy consumption C kW and the driving distance V both approach the value "0", resulting in a convergence of energy efficiency to "0", if only the energy consumption C kW (denominator) has been raised.

[0055] For this reason, the instrument control unit 54 has a distance offset addition module 66, which updates the driving distance or distance V, which is a counter, to a driving distance V. O increased. As expressed by the following equation (6), the distance offset addition module 66, which serves as the travel distance addition module, adds an offset value k. O , which is a second addition value to the distance traveled V, to account for the increased distance traveled V O to calculate.

[0056] In this way, in the situation where energy consumption C kW and as the distance V approaches the value “0”, the energy efficiency converges to “1”, and the energy efficiency can therefore be calculated correctly. VO[km / s]=V[km / s]+kO

[0057] In the preceding description, the same offset value k is used in each case. O regarding energy consumption C kW and the distance traveled V is added. This means that the first and second added values ​​are the same. However, there is no restriction on this, and the first and second added values ​​can also be specified as different values.

[0058] As described above, it is preferred to use the same offset value k. O regarding energy consumption C kW and to add to the distance traveled V, since in the situation where the energy consumption C kWand the driving distance V both approach "0", the energy efficiency can converge to "1" and the energy efficiency is thus calculated correctly. However, the first and second addition values ​​can be specified as different values ​​within a range in which the display content of the ECO display 44, described later, does not show an unnatural operating process.

[0059] In this case, the situation arises where energy consumption C kW and the distance V both approach “0”, resulting in a convergence of energy efficiency to, for example, “1.1” or “0.9” instead of “1”.

[0060] It should be mentioned that according to the above equation (6) a system of units of the distance traveled V O collapses because the offset value k O[kW] is added to the distance traveled V [km / s]. However, as will be described later, a value displayed on the ECO display 44 does not represent the distance traveled V. O , but rather a difference in efficiency between average energy efficiency and current energy efficiency. Therefore, the display content of the ECO indicator 44 does not indicate an unnatural operating process.

[0061] Furthermore, the instrument control unit 54 has an average efficiency calculation module 67, which serves as the first efficiency calculation module. The average efficiency calculation module 67 is provided with the energy consumption C. kWO from the energy offset addition module 65 and the travel distance V O supplied by the distance offset addition module 66.

[0062] The average efficiency calculation module 67 then adds the energy consumption C. kWOthrough an entire initial time period for calculating energy consumption C Total together and add the distance traveled V O during the entire initial period for calculating a travel distance D Total together. As expressed by the following equation (7), the average efficiency calculation module 67 then divides the distance traveled D. Total through energy consumption C Total , to achieve an average energy efficiency E Ave to calculate, which represents an initial energy efficiency.

[0063] It should be noted that the first time period could, for example, be the time from when a trip odometer resets, adding up the distance traveled to the current time, or the time from when the ignition switch is turned on until the current time. Alternatively, the last predetermined time period, such as the last ten minutes, the last hour, or the last ten hours, could be specified as the first time period. EAve[km / kJ]=DTotal[km]:CTotal[kJ]

[0064] The instrument control unit 54 has an instantaneous efficiency calculation module 68, which serves as a second efficiency calculation module. The instantaneous efficiency calculation module 68 is provided with the energy consumption C. kWO from the energy offset addition module 65 and the travel distance V O supplied by the distance offset addition module 66.

[0065] The instantaneous efficiency calculation module 68 then adds the energy consumption C. kWO over an entire second period of time, which is shorter than the first period of time, in order to achieve an energy consumption C Ins to calculate, and it adds the distance traveled V O over the entire second time period together, to cover a distance D Ins to calculate. As expressed by the following equation (8), the instantaneous efficiency calculation module 68 divides the distance traveled D. Ins through energy consumption C Ins , to obtain an instantaneous energy efficiency E Ins to calculate, which is a second energy efficiency factor.

[0066] It should be noted that examples of the second duration include the last 0.1 seconds, the last 0.2 seconds, and the last 1 second. As described above, a shorter duration than the first duration is used to calculate the average energy efficiency E.Ave as a second time period for calculating the instantaneous energy efficiency E Ins specified. Eins[km / kJ]=DIns[km]:CIns[kJ]

[0067] The instrument control unit 54 includes an efficiency difference calculation module 69 and a display control module 70. The efficiency difference calculation module 69 is provided with the average energy efficiency E Ave from the average efficiency calculation module 67 and the current energy efficiency E Ins supplied by the instantaneous efficiency calculation module 68. As expressed by the following equation (9), the efficiency difference calculation module 69 then subtracts the average energy efficiency E. Ave from the current energy efficiency E Ins , to calculate a display value E ECO to calculate, which is an efficiency difference.

[0068] Next, the display control module 70 controls the display content of the ECO display 44, i.e., the length and direction of the display bar 45, based on the display calculation value E. ECO This means that if the instantaneous energy efficiency E, determined based on the current driving style, Ins is high and the display calculation value E ECO If the value is calculated as positive, then the display bar 45 of the ECO display 44 will be shown with a trend towards the positive side.

[0069] If the current energy efficiency E, determined based on the current driving style Ins is low and the display calculation value E ECOIf the value is calculated as negative, then the display bar 45 of the ECO display 44 will show a downward trend. The driver looking at the ECO display 44 can thus identify driving styles that contribute to improved energy efficiency, thereby improving the energy efficiency of the hybrid vehicle 10. EECO[km / kJ]=Eins[km / kJ]−EAve[km / kJ]

[0070] As described above, energy consumption C takes into account kW , which serves as the basis for calculating the display value E ECO serves to dissipate the energy loss C released by the hybrid vehicle 10 BkW Using this energy consumption C kW Can the display calculated value E ECO reflects the proportionate use of the regenerative brake 30 and the friction brake 31, which varies depending on the driving style.

[0071] The driver, looking at the ECO display 44, can thus recognize the driving style that contributes to improved energy efficiency, i.e., the driving style that contributes to a reduced proportionate use of the friction brake 31, and the energy efficiency of the hybrid vehicle 10 can be improved.

[0072] The proportion of regenerative braking 30 used in the total braking torque varies considerably depending on the driving style, i.e., depending on how the brake pedal 32 is actuated. This means that if the brake pedal 32 is lightly depressed and there is still some play in the vehicle braking process, the total braking torque is set low, and the proportion of friction braking 31 used in the total braking torque can be reduced.

[0073] By reducing the proportion of use of the friction brake 31 in the vehicle braking process in this way, the energy loss C released by the friction brake 31 can be reduced. BkWcan be reduced; this can reduce energy consumption C kW They can be reduced, and energy efficiency can be increased. In this case, there is a greater probability that the displayed calculated value E ECO with decreasing energy consumption C kW calculated as a positive value; this allows the driver to detect slight braking, which contributes to improving energy efficiency.

[0074] When the brake pedal 32 is suddenly pressed during vehicle braking, the total braking torque is increased, and thus the proportion of the friction brake 31 in the total braking torque increases. As the proportion of friction brake 31 used increases during vehicle braking, the energy loss C released by the friction brake 31 decreases. BkW to; this increases energy consumption C kW , and energy efficiency decreases.

[0075] In this case, there is a higher probability that the display calculation value E ECO with increasing energy consumption C kW is calculated as a negative value; the driver can thus detect a sudden braking action, which contributes to a deterioration in energy efficiency.

[0076] The following describes the display behavior of the ECO indicator 44 from the start of the vehicle until the vehicle is stopped. Fig. Figure 5 shows a conceptual diagram to illustrate an example of the display behavior of the ECO display 44. As in Fig. As shown in point 5, the current energy efficiency E increases after startup. Ins gradually (X1), as the distance traveled increases with increasing vehicle speed.

[0077] When the degree of deactivation of an accelerator pedal is increased (A1), energy consumption increases, and the instantaneous energy efficiency E Insdecreases (X2). If the degree of deformation of the accelerator pedal is further increased (A2), energy consumption rises, and the instantaneous energy efficiency E Ins decreases (X3) because the combustion engine starts (E1).

[0078] When the accelerator pedal is released (A3), the hybrid vehicle 10 enters a coasting state, gradually slowing down. During this coasting phase, the combustion engine 12 stops (E2), and the regenerative braking system 30 is applied (Ba1). This increases the recovered electrical energy (hereinafter referred to as regenerative energy); consequently, energy consumption decreases, and the instantaneous energy efficiency E Ins increases (X4).

[0079] When the accelerator pedal is pressed during coasting (A4), the combustion engine 12 restarts (E3), and the regenerative braking 30 stops (Ba2). This increases energy consumption and the instantaneous energy efficiency E Ins decreases (X5).

[0080] The accelerator pedal is then released (A5), and the brake pedal 32 is lightly depressed (B1) to decelerate the vehicle to a stop. When the brake pedal 32 is lightly depressed in this way, the internal combustion engine 12 stops (E4), and the regenerative braking power 30 increases to a state (Ba3) in which the friction braking power 31 is held at "0" (Bb1). In this case, energy consumption drops drastically, and the instantaneous energy efficiency E Ins increases significantly (X6) because regenerative energy increases while loss energy is suppressed to “0”.

[0081] When the deformation of the brake pedal 32 is increased (B2) to stop the hybrid vehicle 10, the total braking torque of the hybrid vehicle 10 is brought to a high level. To achieve this total braking torque, which is a target value, the braking power of the regenerative brake 30 is increased (Ba4). However, the braking power of the regenerative brake 30 is limited, for example, by the availability of power from the battery 24; for this reason, the braking power of the friction brake 31 is increased (Bb2) to compensate for the lack of braking power.

[0082] In this case, energy consumption increases, and the current energy efficiency E Ins decreases (X7) because the energy loss increases with the application of the friction brake 31. For example, in the example shown, the driver reduces his application of the brake pedal 32 (B3) immediately before stopping.

[0083] This reduces the overall braking torque of the hybrid vehicle 10 to a low state, and the braking power of the friction brake 31, which had been compensating for the lack of braking power, is reduced (Bb3). The energy loss decreases with the reduction of the braking power of the friction brake 31; this reduces energy consumption and the instantaneous energy efficiency E. Ins increases (X8).

[0084] As described above, the instantaneous energy efficiency E fluctuates. Ins strongly dependent on the operating situations of the accelerator and brake pedals 32. If the instantaneous energy efficiency achieved by the current driving style E Ins is high and the display calculation value E ECO If calculated as a positive value, then the display bar 45 will be set according to the calculated display value E. ECO and displayed with a trend towards the positive side on the ECO display 44.

[0085] If the current energy efficiency achieved through the current driving style E Ins is low and the display calculation value E ECO If calculated as a negative value, the display bar 45 will be adjusted according to the calculated display value E. ECO as well as with a trend towards the negative side on the ECO display 44.

[0086] The driver looking at the ECO display 44 can thus recognize a driving style that contributes to improved energy efficiency, and the energy efficiency of the hybrid vehicle 10 can be improved. It should be noted that the ECO display 44 has a positive limit L1 and a negative limit L2, and the calculated display value E ECO displayed within a range defined by these limits.

[0087] The present invention is not limited to the embodiment described above, and various modifications may occur within the scope of the present invention. In the preceding description, the parallel hybrid vehicle 10 is equipped with the vehicle display device 11. Without limitation, for example, a series or a series / parallel hybrid vehicle may also be equipped with the vehicle display device 11. In a series or a series / parallel hybrid vehicle, an electric motor is driven not only to generate power during regenerative braking, but also by an internal combustion engine to generate power.

[0088] In the preceding description, the hybrid vehicle 10 is equipped with the vehicle display device 11. However, an electric vehicle without an internal combustion engine 12, such as an electric car or a fuel cell car, can also be equipped with the vehicle display device 11. In this case, the fuel energy calculation module 60 in the instrument control unit 54 is omitted. The fuel consumption calculation module 63 of the instrument control unit 54 combines the electrical energy C EkW and the energy loss C BkW to calculate energy consumption C kW per unit of time.

[0089] In the above description, the loss energy C is calculated BkW the generator moment T BR of the total braking torque T TotalThe result is subtracted, and the value is multiplied by the engine revolutions N and the conversion factor kT2P. Without further restriction, for example, the hydraulic brake pressure supplied to brake caliper 35 can be detected, and the energy loss C can be determined. BkW can be calculated based on the value of this hydraulic brake pressure. This means the energy loss C. BkW can be calculated on the basis of a directly detected actuation state of the friction brake 31.

[0090] In the above description, the fuel energy C FkW , the electrical energy C EkW and the energy loss C BkW calculated by converting to "kW", i.e., heat quantity "kJ" per unit of time. Without this restriction, for example, the fuel energy C can be calculated. FkW , the electrical energy C EkW and the loss energy C BkW calculated by converting it into another quantity of heat, such as calories.

[0091] In the preceding description, the offset value k O regarding energy consumption C kW added and furthermore the offset value k O added to the distance traveled V. Without further restriction, for example the instantaneous energy efficiency E can be used. Ins and the average energy efficiency E Ave without increasing energy consumption C kW and the distance traveled V in the case where an unnatural process, which could be indicated by the ECO display 44 in a specific driving situation, occurs, if the energy consumption C kW and the driving distance V cannot be increased, is permissible, or can be suppressed by another method.

[0092] In the above description, the display calculation value E ECO (Efficiency difference) by subtracting the average energy efficiency E Ave from the current energy efficiency E Insis calculated. Without restriction, the display calculated value E ECO (Efficiency difference) also by subtracting the current energy efficiency E Ins of the average energy efficiency E Ave will be calculated.

[0093] In the description above, energy efficiency is calculated by dividing the distance traveled by the energy consumption. Without limitation, energy efficiency can also be calculated by dividing the energy consumption by the distance traveled. In this case, higher energy efficiency values ​​indicate lower energy efficiency, and lower energy efficiency values ​​indicate higher energy efficiency.

[0094] In the preceding description, the onboard display device is display device 41, which displays the ECO indicator 44. Without limitation, the onboard display device could be, for example, an analog or digital instrument whose indicator needle is based on the calculated display value E. ECO is activated, or to create a light-emitting body whose color and flashing pattern are based on the display calculation value E ECO change.

[0095] In the preceding description, a disc brake is used as the friction brake 31. A drum brake can also be used without limitation. Furthermore, a hydraulic friction brake, which controls the brake caliper 35 by hydraulic brake pressure, is used as the friction brake 31. An electric friction brake, which controls the brake caliper 35 by an electric actuator, can also be used without limitation.

[0096] Although the preferred embodiment of the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited thereto. It is understood by those skilled in the art that various modifications or variations are possible, provided they fall within the technical scope of the attached claims or their equivalents. It is understood that such modifications or variations also fall within the technical scope of the present invention. Reference symbol list 10 electric vehicles 11 Vehicle display device 12 Internal combustion engine 13 Motor / Generator 14 Drive unit 15 Primary disk 16 Secondary disk 17 continuously adjustable gears 18 Clutch 19 Output wave 20 Differential mechanism 21 wheels 22 Stator 23 Inverter 24 Battery (electrical storage device) 30 Regeneration brake 31 Friction brake 32 Brake pedal 33 Master cylinders 34 disc rotor 35 brake caliper 36 Hydraulic unit 40 Instrument cluster 41 Display device 42 tachometer 43 Tachometer 44 ECO display 45 display bars 50 Internal combustion engine control unit 51 Hybrid control unit 52 Battery control unit 53 Brake control unit 54 Instrument Control Unit 55 vehicle-owned network 60 Fuel Energy Calculation Module 61 Electrical Energy Calculation Module 62 Loss Energy Calculation Module 63 Consumption Calculation Module 64 Route Calculation Module 65 energy offset addition module 66 Distance Offset Addition Module 67 Average efficiency calculation module 68 Instantaneous efficiency calculation module 69 Efficiency Difference Calculation Module 70 Display control module

Claims

Vehicle display device for an electric vehicle (10) with a friction brake (31), wherein the vehicle display device (11) comprises: - a loss energy calculation module (62) that calculates a loss energy released by the electric vehicle (10) based on an actuation state of the friction brake (31), wherein, in calculating the loss energy, a regenerative torque is subtracted from a total braking torque, wherein the regenerative torque is a torque generated by an electric motor (13) of the electric vehicle during regenerative braking and the total braking torque is a braking torque required for a vehicle braking operation of the electric vehicle (10); - an electrical energy calculation module (61) that calculates an electrical energy consumed or generated by the electric vehicle (10) based on a charging / discharging power of an electrical storage device (24) present in the electric vehicle (10);- a consumption calculation module (63) that calculates the energy consumption of the electric vehicle (10) based on energy loss and electrical energy; - a first efficiency calculation module (67) that calculates a first energy efficiency based on a distance traveled and energy consumption over a first period of time; - a second efficiency calculation module (68) that calculates a second energy efficiency based on a distance traveled and energy consumption over a second period of time that is shorter than the first period of time; and - a display control module (70) that controls the display content of an on-board display device (41) based on an efficiency difference between the first energy efficiency and the second energy efficiency. Vehicle display device according to claim 1, wherein the vehicle display device further comprises: - a fuel energy calculation module (60) that calculates fuel energy consumed by the electric vehicle (10) on the basis of a quantity of fuel injected by an internal combustion engine (12) present in the electric vehicle (10), wherein the consumption calculation module (63) calculates the energy consumption on the basis of the energy loss, the electrical energy and the fuel energy. Vehicle display device according to claim 1 or 2, wherein the energy loss calculation module (62) calculates the energy loss as a quantity of heat, and wherein the electrical energy calculation module (61) calculates the electrical energy as a quantity of heat. Vehicle display device according to one of claims 1 to 3, wherein the loss energy calculation module (62) calculates the loss energy as a quantity of heat, wherein the electrical energy calculation module (61) calculates the electrical energy as a quantity of heat, and wherein the fuel energy calculation module (60) calculates the fuel energy as a quantity of heat. Vehicle display device according to one of claims 1 to 4, wherein the vehicle display device further comprises: a consumption addition module (65) which adds a first addition value to the energy consumption in order to update the energy consumption and which outputs the updated energy consumption to the first efficiency calculation module (67) and the second efficiency calculation module (68). Vehicle display device according to one of claims 1 to 5, wherein the vehicle display device further comprises: - a distance addition module (66) which adds a second addition value to the distance traveled in order to update the distance traveled and which outputs the updated distance traveled to the first efficiency calculation module (67) and the second efficiency calculation module (68). Vehicle display device according to claims 5 and 6, wherein the first addition value and the second addition value are the same value.

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