JP2012152096A - Kinetic efficiency determination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a kinetic efficiency determination device for properly determining a kinetic efficiency of a vehicle in EV vehicles, HEV vehicles or PHEV vehicles.SOLUTION: An energy consumption rate Ecj [kJ/m], which is energy consumption per unit distance in EV running in EV vehicles, HEV vehicles and PHEV vehicles, is calculated such that, in addition to increase and decrease of a kinetic energy Ei and increase and decrease of a potential energy Ep, increase and decrease of an electric energy Eb is also taken into consideration. Accordingly, a kinetic efficiency of a vehicle can be properly determined even in EV running in EV vehicles, HEV vehicles or PHEV vehicles.

Description

  The present invention relates to an exercise efficiency determination device that accurately determines the exercise efficiency of a vehicle.

  2. Description of the Related Art Conventionally, a technique for providing an index for use in fuel-saving driving support to a user such as a vehicle driver has been disclosed.

Patent Document 1 proposes an effective fuel consumption MPGeff expressed by the following equation (1) as an index for providing fuel-saving driving support for an internal combustion engine vehicle (hereinafter referred to as an engine vehicle).
MPGeff = Vavg × D × Δt × ΔHr / (Ef−ΔEke−ΔEpe)
... (1)

In the equation (1), the kinetic energy change ΔEke is calculated by the following equation (2).
ΔEke = (1/2) × m × (Vi−Vi−1) ² (2)

In the equation (1), the potential energy change ΔEpe is calculated by the following equation (3).
ΔEpe = m × g × (Hi−Hi−1) (3)

  In the above equations (1) to (3), Δt is a predetermined time (unit time), Vavg is an average speed per predetermined time Δt, D is a gasoline density, for example, 0.72 [g / cc], and ΔHr is a combustion process. For example, 43 [kJ / gm], Ef is the combustion energy (chemical energy), m is the mass of the vehicle, (Vi-Vi-1) is the change in the vehicle speed V during the predetermined time Δt, g Is the gravitational acceleration, and (Hi-Hi-1) is the change in position (height) during a predetermined time Δt.

  The energy consumption can be evaluated even under conditions such as acceleration / deceleration, uphill, downhill, etc., by the effective fuel consumption MPGeff (index of motion efficiency) expressed by equation (1).

US Pat. No. 5,578,748

  However, recently, in the electric vehicles (hereinafter referred to as EV vehicles), hybrid vehicles (hereinafter referred to as HEV vehicles), or plug-in hybrid vehicles (hereinafter referred to as PHEV vehicles) that are proposed or marketed. In the effective fuel consumption MPGeff related to the engine vehicle of formula (1), the inventor of this application has found that a case that does not correspond occurs.

  For example, if the HEV vehicle is running at a constant speed on a road with zero inclination only by electric energy with engine combustion stopped, all three terms of the denominator of the effective fuel consumption MPGeff are all zero values (Ef = 0, Since ΔEke = 0 and ΔEpe = 0), the value of the effective fuel consumption MPGeff cannot be calculated (MPGeff → ∞).

  The present invention has been made in consideration of such a problem, and provides a motion efficiency determination device that can accurately determine the motion efficiency of a vehicle in an engine vehicle, an EV vehicle, an HEV vehicle, or a PHEV vehicle. The purpose is to provide.

  The motion efficiency determination device according to the present invention is a motion efficiency determination device for determining the motion efficiency of a vehicle, the vehicle speed detection means detecting the speed of the vehicle, and the altitude detection means detecting the altitude of the road on which the vehicle travels. Power detection means for detecting the power consumption of the motor for driving, kinetic energy calculation means for calculating kinetic energy according to the mass of the vehicle and the vehicle speed detected by the vehicle speed detection means, and the altitude detection means A potential energy calculating means for calculating potential energy according to the detected altitude; an electric energy calculating means for calculating electric energy according to the power consumption detected by the power detecting means; and an energy consumption rate calculating means. And the energy consumption rate calculating means calculates the energy consumption rate of the vehicle by the kinetic energy, the potential energy, and the electric energy. And wherein the Mel.

  According to the present invention, the energy consumption rate (energy consumption per unit distance) during EV traveling in an EV vehicle is calculated in consideration of increase / decrease in kinetic energy, increase / decrease in potential energy, and increase / decrease in electrical energy. Since it did in this way, the exercise | movement efficiency of a vehicle can be determined accurately also at the time of EV driving | running | working of EV vehicle, HEV vehicle, and PHEV vehicle.

  In this case, a fuel injection amount detecting means for detecting the fuel injection amount and a combustion energy calculating means for calculating combustion energy according to the fuel injection amount detected by the fuel injection amount detecting means are provided, and the energy The consumption rate calculating means obtains an energy consumption rate of the vehicle from energy obtained by adding the combustion energy to the kinetic energy, the potential energy, and the electric energy.

  According to the present invention, it is possible to calculate an energy consumption rate as an index of vehicle movement efficiency in an engine vehicle, HEV vehicle, or PHEV vehicle.

  When the vehicle is running, the energy consumption rate is obtained by dividing the sum of the combustion energy, the kinetic energy, the position energy, and the electric energy by the travel distance detected by the travel distance detection means. And when the vehicle is stopped, the vehicle energy is calculated by dividing the sum of the combustion energy and the electric energy by the stop time.

  According to the present invention, it is possible to calculate the energy consumption rate as an index of the motion efficiency of the vehicle in the HEV vehicle or the PHEV vehicle by an optimal calculation method for running and stopping.

  In the HEV vehicle or PHEV vehicle that performs idle stop control by stopping fuel injection when it is determined that the vehicle has stopped, when the vehicle is stopped, the energy consumption rate is set to the electric energy value. What is necessary is just to calculate by dividing by the said stop time.

  In addition to using an altitude sensor, the altitude detecting means can detect the altitude of the road according to the road gradient detected by the road gradient detecting means and the travel distance detected by the travel distance detecting means. .

  The road gradient detecting means for detecting the road gradient can be detected not based on the inclination sensor (gradient sensor) itself but based on the brake fluid pressure and the acceleration of the vehicle. By detecting the road gradient based on the brake fluid pressure and the vehicle acceleration, the energy consumption rate reflecting the energy consumption of the kinetic energy can be appropriately calculated even during the braking operation.

  The mass of the vehicle may be the mass of the vehicle main body + the mass of the driver (set value), but more precisely, the mass of the vehicle body and the mass of the passenger and the luggage are added to the mass of the vehicle main body. In view of the above, it is preferable to set a value (corrected mass) obtained by adding the mass of the vehicle body to the mass converted value of the output value of the suspension stroke sensor (occupant mass + luggage mass).

  According to this invention, by calculating the energy consumption rate as an index of the vehicle's movement efficiency in the EV vehicle, HEV vehicle, or PHEV vehicle, it is possible to accurately determine the vehicle's movement efficiency. In addition, the energy consumption rate can be calculated in an optimal calculation direction during traveling and when stopped.

  Further, the energy consumption rate as an index of the vehicle's motion efficiency can be calculated in an HEV vehicle or PHEV vehicle by an optimal calculation method during traveling and when stopped.

It is a block diagram which shows schematic structure of the HEV vehicle by which the exercise efficiency determination apparatus which concerns on this embodiment is mounted. It is a flowchart with which it uses for operation | movement description of the HEV vehicle of the example of FIG. FIG. 3A is an explanatory diagram of a display example of the display, and FIG. 3B is an explanatory diagram of another display example of the display. It is explanatory drawing which shows the correspondence of energy loss and energy consumption. It is a block diagram which shows schematic structure of the HEV vehicle by which the exercise efficiency determination apparatus which concerns on other embodiment is mounted. It is a characteristic view which shows the relationship between brake fluid pressure and acceleration. It is a characteristic view which shows the relationship between a front load and a front sensor output. It is a characteristic view which shows the relationship between a rear load and a rear sensor output.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an exercise efficiency determination device according to the present invention will be described with reference to the accompanying drawings by giving preferred embodiments in relation to a vehicle equipped with the exercise efficiency determination device.

  FIG. 1 is a block diagram showing a schematic configuration of an HEV vehicle (hereinafter also simply referred to as a vehicle) 10 in which the exercise efficiency determination device according to this embodiment is mounted.

  The HEV vehicle 10 includes an engine 12 and a traveling motor 14 as power sources. The HEV vehicle 10 travels when power generated on the output shaft of the engine 12 or the traveling motor 14 is transmitted to wheels through the axle via a transmission (not shown).

  The combustion of the engine 12 is adjusted by a fuel injection amount cf [cc] injected into the engine from the fuel injection device 20 connected to the fuel tank 18 under the control of a FI-ECU (Fuel Injection-Electronic Control Unit) 16. The

  The fuel injection amount cf [cc] is supplied from the FI-ECU 16 to the meter ECU 22.

  During power running, the traveling motor 14 receives an AC drive signal from a vehicle-mounted battery (power storage device) 24 through a power converter 26 such as an inverter, and the output shaft rotates. Further, during regeneration, the traveling motor 14 functions as a generator, and the battery 24 is charged through the power conversion device 26 by the electric power generated in the traveling motor 14.

  A power sensor 28 is inserted between the battery 24 and the power converter 26, and power consumption (including charging power) P [W] measured by the power sensor 28 is supplied to the meter ECU 22.

  The altitude sensor 30 detects the altitude (altitude above sea level) h [m] and supplies it to the meter ECU 22. The altitude sensor 30 can be replaced with reception height information in a GPS receiver included in a navigation device (not shown).

  The inclination sensor 32 detects a road gradient θ [°], which is an inclination angle in the traveling direction of the vehicle 10, and supplies it to the meter ECU 22. In addition to the inclination sensor 32, the road gradient θ [°] can also be obtained as an integrated value of the output in the pitching direction (front-rear direction of the vehicle) of a three-axis acceleration sensor (not shown) mounted on the vehicle.

  The vehicle speed sensor 34 supplies the vehicle speed V [m / s] to the meter ECU 22.

  The distance sensor 36 supplies a travel distance d [m] such as a trip travel distance to the meter ECU 22. The travel distance d [m] can be obtained from travel distance information of a navigation device (not shown) including a positioning device and map information instead of the distance sensor 36.

  The main switch 38 supplies an ignition signal Ig (Ig = on or off) of the vehicle 10 to the meter ECU 22.

  The meter ECU 22 is further connected with a multi-information display (multiple information display device, hereinafter simply referred to as a display) 40 disposed on the dashboard of the vehicle 10 for the convenience of a user such as a driver. The

  In this embodiment, the display 40 includes an eco guide (energy saving guide) 42 as an energy saving driving support index (economic driving support index) and an energy consumption rate Ecj [kJ / m] corresponding to exercise efficiency, respectively. Is displayed. The fuel consumption [km / L] can also be displayed.

  The eco guide 42 and / or the energy consumption rate Ecj may be displayed on the entire screen or a partial screen of the display for the navigation apparatus, in addition to being displayed on the display 40 or instead of the display 40.

  In this embodiment, the eco guide 42 for the energy consumption rate Ecj [kJ / m] is displayed by the length of the green bar 44. The lower the energy consumption rate Ecj, the longer the bar length. When the energy consumption rate Ecj is lower, the so-called energy saving operation rate is higher, and the energy consumption rate Ecj is compared with a threshold value. When the energy consumption rate Ecj is smaller than the threshold value, the bar is displayed in green and the value is larger. The bar can be displayed in red, and various changes can be made according to the degree of energy saving operation.

  The meter ECU 22 is a computer including a microcomputer, a CPU (central processing unit) 46, a ROM (including an EEPROM) as a memory (storage unit) 48, a RAM (random access memory), and other A / D converters. , An input / output device (I / O) 50 such as a D / A converter, a timer 51 as a timekeeping unit, and the like, and the CPU 46 reads out and executes a program recorded in the ROM, thereby realizing various functions. Function as.

  In this embodiment, the meter ECU 22 (hereinafter also simply referred to as the ECU 22) includes a kinetic energy calculating means (Ei calculating means) 52, a potential energy calculating means (Ep calculating means) 54, and an electric energy calculating means (Eb calculating means) 56. , Combustion energy calculation means (Ef calculation means) 58, energy consumption rate calculation means (Ecj calculation means) 60, and the like.

  Next, the operation of the above embodiment will be described with reference to the schematic flowchart shown in FIG. 2 corresponding to the program stored in the memory 48.

  In step S1, the ECU 22 (or the CPU 46) determines whether or not the main switch 38 is turned on by turning on and off the ignition signal Ig.

  If the ignition signal Ig is in the on state, the ECU 22 counts a predetermined time, for example, 0.1 seconds, by the timer 51 in step S2.

  When the elapse of the predetermined time by the timer 51 is detected, in step S3, the ECU 22 takes in the physical quantity described below into the memory 48. Since the energy consumption Es [kJ] for a predetermined time cannot be calculated in the first physical quantity capturing process, the following description will be made assuming that the process is the second and subsequent capturing processes.

  In step S3, the ECU 22 receives the fuel injection amount cf [cc] from the FI-ECU 16, the power consumption (or charging power) P [W] from the power sensor 28, and the height h [m] from the altitude sensor 30. The vehicle speed sensor 34 captures (stores) the vehicle speed V [m / s] and the distance sensor 36 the travel distance d [m], respectively.

  In this step S3, the ECU 22 sets the physical quantity taken into the memory 48, and the fuel injection quantity cf [cc] is set to a value for a predetermined time (sampling time and called elapsed time t). ] Is the value of elapsed time t, height h [m] is the value of the altitude difference of elapsed time t, vehicle speed V [m / s] is the average value of elapsed time t, and travel distance d [m]. ] Are converted into travel distances of elapsed time t, respectively. The value used below shall be this converted value. Actually, the elapsed time t is a predetermined time measured by the timer 51, and preferably outputs an average value obtained by storing the energy consumption rate calculated at intervals of 0.1 seconds for a plurality of times. By doing so, the change in the length display of the bar 44 of the eco guide 42 becomes smooth.

The amount of change in the height h [m] is determined from the road gradient θ [°] detected by the inclination sensor 32 and the travel distance d [m] between the elapsed time t without using the altitude sensor 30. (1) can also be obtained.
h [m] = d · sin θ (1)

  Next, in step S4, the ECU 22 determines whether or not the vehicle 10 is traveling based on the vehicle speed V [m / s]. When the vehicle speed V [m / s] is zero, it is determined that the vehicle is not running but is stopped, and when the vehicle speed V [m / s] is a finite value (non-zero value), judge.

When it is determined that the vehicle is traveling, in step S5, the ECU 22 calculates an energy consumption amount Ea [kJ] during traveling of the vehicle 10 by the following equation (2).
Ea [kJ] = Ef + Eb + Ei + Ep (2)

  Here, Ef is combustion energy, Eb is electrical energy, Ei is kinetic energy, and Ep is potential energy, which can be obtained by the following equations (3) to (6), respectively.

Ef [kJ] = cf · e · η (3)
Here, cf [cc] is the fuel injection amount, and e [kJ / cc] is the heat value of the fuel. For example, in the case of ordinary gasoline, e = 35 [kJ / cc] is a fixed value. η is the thermal efficiency of the engine 12, and in this embodiment, η = 0.33 (depending on the vehicle 10) is used.

Eb [kJ] = P · t / 0.278 (4)
Here, P [W] is power, and t [h] is a time-converted value of the above-described elapsed time t, that is, 2.77 × 10 ⁻⁵ [h] ≈0.1 [s].

Ei [kJ] = m (V1 -V0) 2/2 ... (5)
Here, m [kg] is the mass of the vehicle 10 (more preferably a value obtained by adding the mass of a passenger such as a driver to the vehicle weight using a weight sensor or the like), V1, V0 [m / s]. Is the vehicle speed and indicates the current vehicle speed V1 and the previous vehicle speed V0 during the elapsed time t (calculation cycle).

Ep = m · g · (h1−h0) = m · g · d · sin θ (6)
Here, m [kg] is mass, g [m / s ² ] is gravitational acceleration, h1, h0 [km] is height, and this height h1 between elapsed time t (calculation cycle) and Indicates the previous height h0. d [km] is the travel distance during the elapsed time t, and θ [°] is the road gradient.

Next, in step S6, the ECU 22 calculates an energy consumption rate Ecj [kJ / m], which is an energy consumption amount per unit distance of the vehicle 10, by the following equation (7).
Ecj [kJ / m] = Ea / d = (Ef + Eb + Ei + Ep) / d (7)

  Here, d [km] is the travel distance during the elapsed time t. As described above, Ea [kJ] is energy consumption, Ef is combustion energy, Eb is electrical energy, and Ei is motion. Energy, Ep is potential energy. In addition, it can be said that the energy consumption rate Ecj is operating more economically because the energy consumption per unit distance decreases as the value decreases.

  In this case, the ECU 22 takes only a positive value because the combustion energy Ef is consumed by fuel injection. The electric energy Eb takes a positive value when discharged (consumed), and takes a negative value when regeneratively charged. The kinetic energy Ei is a negative value because energy is stored during acceleration, and is positive because energy is consumed during deceleration. Further, the potential energy Ep is set to a negative value because energy is stored in the uphill direction, and is set to a positive value because energy is consumed in the downhill direction. Note that in EV vehicles and PHEV vehicles, the electric energy Eb takes a positive value in the consumption direction.

  Thus, in this embodiment, as shown in FIG. 4, the energy loss of EV vehicle, HEV vehicle 10 and PHEV vehicle is engine loss, mechanical transmission loss, electrical / auxiliary loss, travel transmission loss, and brake. We paid attention to the direct connection to eco-driving by suppressing the total loss (sum) of losses such as heat loss. However, considering that it is extremely difficult to calculate these values during driving, as a result of earnest study, the total energy loss of these energy losses is calculated according to the law of conservation of energy, the consumption of kinetic energy Ei, It was noted that the consumption amount of potential energy Ep, the consumption amount of electric energy Eb, and the consumption amount of combustion energy Ef are equal to the total (sum total) energy consumption amount.

  Therefore, by measuring the energy consumption during traveling, the energy consumption is calculated every moment and displayed as the energy consumption rate Ecj, and the driver operates so that the energy consumption rate Ecj is small (low). This led to the idea that fuel economy and electricity consumption could be improved.

  Based on these considerations, in step S7, the ECU 22 displays the calculated energy consumption rate Ecj as shown in the display content in the enclosure of the display 40 of FIG.

The unit of the energy consumption rate Ecj to be displayed is [kJ / m]. However, the unit is not limited to this, and the ECU 22 that also operates as a unit switching unit by operating an input device (not shown) is, for example, As shown in the following equations (8) and (9), energy consumption rate Ecm [km / L] (so-called fuel consumption) (see FIG. 3A) or energy consumption rate Ecw [Wh / m] (so-called reciprocal of electricity consumption) ) (See FIG. 3B) and the unit can be switched based on a simple calculation. Changing the setting so that at least two of energy consumption rate Ecj [kJ / m], energy consumption rate Ecm [km / L], and energy consumption rate Ecw [Wh / m] are displayed alternately or simultaneously. You can also.
Ecm [km / L] = d / (Ef + Eb + Ei + Ep) / η / e
= 1 / Ecj / η / e (8)
Ecw [Wh / m] = 0.278 (Ef + Eb + Ei + Ep) / d
= 0.278 Ecj (9)

  In the case of the display of the energy consumption rate Ecm [km / L] (so-called fuel consumption) in FIG. 3A, the length of the bar 44 of the eco guide 42 becomes shorter as the fuel consumption becomes worse (lower), and the energy in FIG. Note that in the case of display of the consumption rate Ecw [Wh / m] (so-called reciprocal of electricity consumption), the length of the bar 44 of the eco guide 42 becomes shorter as the reciprocal of electricity consumption becomes smaller.

In step S4 described above, when the ECU 22 determines that the vehicle 10 is stopped, the kinetic energy Ei is zero, so that the energy consumption amount Eas [ kJ] is calculated by the following equation (10) or (11).
Eas [kJ] = Ef + Eb (when there is no so-called idle stop control)
(10)
Eas [kJ] = Eb (when so-called idle stop control is performed)
... (11)

  In the idle stop control, for example, when the FI-ECU 16 detects that the vehicle speed V is V = 0 [km / h] and the foot brake is stepped on, the fuel injection device 20 performs fuel injection to the engine 12. Control that stops. This stop control is detected by the ECU 22.

And when it determines with the vehicle 10 having stopped, as shown to step S9, ECU22 is not energy consumption rate Ecj [kJ / m] which is the energy consumption amount per unit distance, but the following (12). As shown in the equations (13) and (13), the energy consumption rate Ecs [kJ / min], which is the energy consumption per unit time, may be calculated and displayed.
Ecs [kJ / min] = (Ef + Eb) / t (when so-called idle stop control is not performed) (12)
Ecs [kJ / min] = Eb / t (when so-called idle stop control is performed) (13)

  In Expressions (12) and (13), t is an elapsed time (stop time) while the vehicle is stopped, but may be a unit time for calculating every predetermined period while the vehicle is stopped.

  As described above, the HEV vehicle 10 equipped with the motion efficiency determination device for determining the motion efficiency of the vehicle 10 according to the above-described embodiment is a fuel injection device as fuel injection amount detection means for detecting the fuel injection amount cf [cc]. 20, a vehicle speed sensor 34 as vehicle speed detection means for detecting the speed V [m / s] of the vehicle 10, an altitude sensor 30 as height detection means for detecting the height h [km] of the vehicle 10, A power sensor 28 serving as a power detection unit that detects power consumption P [W] of the motor 14, a distance sensor 36 serving as a travel distance detection unit that detects the travel distance d [m] of the vehicle 10, and the fuel injection device 20. Ef calculation means 58 for calculating combustion energy Ef [kJ] according to the detected fuel injection amount cf [cc], and the mass m [kg] of the vehicle 10 and the vehicle speed sensor 34 are detected. The Ei calculating means 52 for calculating the kinetic energy Ei according to the speed V [m / s], the Ep calculating means 54 for calculating the potential energy Ep according to the height h [km] of the vehicle, and the power sensor 28. Eb calculating means 56 for calculating electric energy Eb according to the detected power consumption P [W], and Ecj calculating means 60 for calculating an energy consumption rate Ecj. Ecj calculating means 60 includes combustion energy Ef and The energy consumption rate Ecj of the vehicle 10 is determined by the above equation (7) from the kinetic energy Ei, the positional energy Ep, and the electric energy Eb.

  According to this embodiment, the energy consumption rate Ecj [kJ / m] at the time of EV traveling in the HEV vehicle 10 is taken into consideration the increase / decrease of the kinetic energy Ei, the increase / decrease of the potential energy Ep, and the increase / decrease of the electric energy Eb. Since the calculation is made, it is possible to accurately determine the motion efficiency of the vehicle other than the HEV vehicle 10 during EV travel of the EV vehicle or the PHEV vehicle.

  Further, according to this embodiment, it is described that both the inclination sensor 32 and the distance sensor 36 are used in place of the altitude sensor 30 in order to obtain the difference in altitude of the vehicle. Alternatively, the gradient may be obtained based on changes in engine torque and vehicle speed V. Thereby, since the inclination sensor 32 becomes unnecessary, the number of parts can be reduced.

  Further, although the distance sensor 36 is used to obtain the travel distance d, the travel distance d may be obtained from the vehicle speed V detected by the vehicle speed sensor 34 and the travel time t (d = V · t). ). Thereby, since the distance sensor 36 becomes unnecessary, the number of parts can be reduced.

  Further, an energy consumption rate Ecj [kJ / m] that is an energy consumption amount per unit travel distance is calculated during traveling, and an energy consumption rate Ecs [kJ / min] that is an energy consumption amount per unit time during stoppage. ] Can be calculated and displayed on the HEV vehicle 10 or the PHEV vehicle by an optimum calculation method during traveling and when stopped.

  According to this embodiment, an accurate index for providing fuel-saving driving support to a user such as a driver of the vehicle 10 is provided.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the contents described in this specification.

  For example, FIG. 5 uses a brake fluid pressure sensor 62 mounted on a vehicle such as the HEV vehicle 10A in place of the tilt sensor 32, and further uses the vehicle mass m [kg] (here, the vehicle main body Sustain stroke sensor 64 to calculate the actual mass m [kg] corrected for (mass) {actual mass corrected by adding the mass of the occupant and the mass of the load to the mass of the vehicle main body (also referred to as corrected mass)}. The structure of 10 A of HEV vehicles by which the exercise efficiency apparatus which concerns on other embodiment using this was mounted is shown. As the suspension stroke sensor 64, a sensor mounted for the automatic optical axis adjustment of the headlight can be used.

  As is well known, the brake fluid pressure sensor 62 is configured to apply the hydraulic pressure when a braking force is applied to a wheel through a hydraulic control mechanism and a brake actuator in accordance with an operation amount (depression amount) of a driver's foot brake pedal. The hydraulic pressure of the control mechanism is detected as the brake hydraulic pressure B [kPa].

  Further, as is well known, the suspension stroke sensor 64 is provided in each of the front suspension and the rear suspension, and changes in the amount of expansion / contraction of each shock absorber (damper) of the front suspension and the rear suspension due to the application of the front load and the application of the rear load. The amount (stroke change amount) S [m] is detected as a voltage change amount or the like.

  First, a method for calculating the road gradient θ [°] from the brake fluid pressure B [kPa] detected by the brake fluid pressure sensor 62 will be described. Here, the road gradient θ [°] is calculated as tangent tan θ = Slope (unit: [%]).

From simulation or experimental confirmation, it was found that the brake fluid pressure B [kPa] and the acceleration α [m / s ² ] are in a proportional relationship. That is, the acceleration α [m / s ² ] (deceleration acceleration) increases in proportion to the increase in the brake fluid pressure B [kPa]. Although the proportionality constant is negative, the value of the proportionality constant varies depending on the vehicle type.

  FIG. 6 is a characteristic diagram showing the relationship between the brake fluid pressure B and the acceleration α of a vehicle of a certain vehicle type, here HEV vehicle 10A.

  A dotted line characteristic 100 indicates a relationship between the brake hydraulic pressure B and the acceleration α on a flat road (Slope = 0 [%]). When the acceleration α on the flat road is αf, the characteristic 100 is expressed as follows. (14).

αf = − {(α0−α1) / B1} B−α0 (14)
Here, α0 is an offset value when B = 0, and α1 is an acceleration α when B = B1.

  The characteristic 102 is a negative value with a known road slope Slope on a downward slope, the characteristic 104 is a positive value with an upward slope known with the road slope Slope, and the characteristic 106 is a positive value with an upward slope known with the road slope Slope. Further, the slope is steeper than the road slope Slope of the characteristic 104. Note that characteristic 100, characteristic 102, characteristic 104, and characteristic 106 have parallel slopes with a downward slope that differ only in the offset value when B = 0.

  From these characteristics 100, 102, 104, and 106 (all of which road gradient Slope is known), acceleration (reference acceleration) αr per 1% of road gradient (unit gradient) was obtained.

In this embodiment, when the road gradient Slope increases by 1 [%] at the same brake fluid pressure B, the acceleration (deceleration acceleration) α is required to increase by αr = −0.1 [m / s ² ]. It was.

Therefore, an arbitrary road gradient Slope can be calculated by the following equation (15).
Slope = Δα × 1 [%] / αr (15)

Here, Δα indicates the difference between the acceleration α (measured value) with respect to the brake fluid pressure B (measured value) and the acceleration αf on a flat road at the road gradient Slope to be obtained. That is, Δα can be calculated by the following equation (16).
Δα = α−αf
= Α-[-{(α0-α1) / B1} B-α0]
= Α + {(α0−α1) / B1} B + α0 (16)

By substituting the equation (16) into the equation (15), it is understood that the road gradient Slope is obtained by the following equation (17).
Slope = [α + {(α0−α1) / B1} B + α0] / αr (17)

In the equation (17), the variable acceleration α can be obtained by a known process by the vehicle acceleration calculating means 68 from the vehicle speed V [m / s] measured by the vehicle speed sensor 34. In this case, what is necessary is just to obtain | require the change rate of the vehicle speed Vs between elapsed time t (calculation period). That is, it can be obtained by the following equation (18) from the current vehicle speed V1 and the previous vehicle speed V0 during the elapsed time t (calculation cycle).
α = (V1−V0) / t (18)

  Therefore, the road gradient calculation means 66 is an acceleration determined based on the brake fluid pressure B [kPa] measured by the brake fluid pressure sensor 62 and the vehicle speed V [m / s] measured by the vehicle speed sensor 34, each of which is a variable. A road gradient Slope can be obtained by substituting α into the equation (17).

  By converting the road gradient Slope [%] obtained by the equation (17) into the road gradient θ [°], the potential energy Ep can be obtained by the equation (6).

  Therefore, according to another embodiment shown in FIG. 5, it is possible to estimate the road gradient θ [°] necessary for obtaining the potential energy Ep even during the operation of the foot brake. That is, even during the operation of the foot brake, the energy consumption rate Ecj [kJ / m] shown in the equation (7) in consideration of the fluctuation of the potential energy Ep can be calculated.

  Next, the mass of the vehicle using the suspension stroke sensor 64 (here, the mass m of the vehicle body (hereinafter referred to as me), the so-called empty mass me) is added to the mass m1 of the occupant + the luggage. The corrected actual mass (also referred to as corrected mass) is hereinafter referred to as corrected mass m [kg] for convenience of understanding. }, The method of calculation by the corrected mass calculation means 70 will be described.

The corrected output amount m can be obtained by the following equation (19) in which the occupant + load mass m1 is added to the empty state mass me.
m = me + m1 (19)

  Here, the mass m1 of the occupant + luggage is the total value of the change in the load applied to the front suspension and the change in the load applied to the rear suspension, so the front suspension stroke sensor 64 (64f) has a front. Relationship (characteristic) between the sensor output Vsf [V] and the front load Wf [kg], and relationship (characteristic) between the rear sensor output Vsr [V] of the rear suspension stroke sensor 64 (64r) and the rear load Wr [kg]. ) In advance, the front sensor output Vsf and the rear sensor output Vsr can be detected, so that an arbitrary (occupant + luggage) mass m1 can be obtained.

  FIG. 7 shows a characteristic 112 and a characteristic 114 corresponding to the relationship between the front load Wf measured at rest and the front sensor output Vsf, and further shows a characteristic 110 of a correlation approximation formula that approximates the characteristic 112 and the characteristic 114. .

  A characteristic 112 of the front sensor output Vsf indicated by a right-up arrow when an object is placed on the front seat (applying a load) and a left-down arrow when the object is lowered (load is reduced) In the characteristic 114 of the front sensor output Vsf shown, there is hysteresis, but this hysteresis occurs due to the friction of the front suspension.

The correlation approximate expression of the front load Wf indicated by the straight line of the characteristic 110, that is, the linear expression of the characteristic 110 is Vsf = (inclination of the straight line of the characteristic 110) × Wf + Vsf0 = {(Vfs1−Vsf0) / Wf1} × Wf + Vsf0. It can be expressed by the following equation (20) solved by Wf.
Wf = {Wf1 / (Vsf1-Vsf0)} (Vsf-Vsf0) (20)

  Here, Wf1 is a known load of a heavy article placed on the front seat, and Vsf0, Vsf1 are the same as when the heavy article with the load Wf1 is not placed on the front seat (Vsf0: offset value) ( Vsf1) is a read value of each front sensor output Vsf. In the equation (20), {Wf1 / (Vsf1-Vsf0)} represents a change amount of the front load Wf per 1 [V].

  FIG. 8 shows a characteristic 122 and a characteristic 124 corresponding to the relationship between the rear load Wr measured at rest and the rear sensor output Vsr, and further shows a characteristic 120 of a correlation approximate expression in which the characteristic 122 and the characteristic 124 are approximated.

  The characteristic 122 of the rear sensor output Vsr when an object is placed on the rear seat (applying a load) and the characteristic 124 of the rear sensor output Vsr when the object is lowered (decreasing the load) are substantially the same.

The correlation approximate expression of the rear load Wr can be expressed by the following expression (21) in the same manner as the expression (20).
Wr =-{Wr1 / (Vsr1-Vsr0)} (Vsr-Vsr0)
... (21)

  Here, − {Wr1 / (Vsr1−Vsr0)} is the amount of change in the rear load Wr per 1 [V], Vsr0 is the rear sensor output Vsr = Vsr0 and Vsr1 is the rear load when the rear load Wr = 0. The rear sensor output Vsr = Vsr1 when Wr = Wr1 (known). Although the rear sensor output Vsr has an inverse slope with respect to the front sensor output Vsf, the output of the suspension stroke sensor 64r is merely using a sensor whose voltage decreases as the load increases. By reversing, it is possible to obtain a characteristic that rises to the right.

  Therefore, the equation (19) can be transformed into the following equation (22), and the correction mass m can be obtained by detecting the front sensor output Vsf and the rear sensor output Vfr and substituting them into the equation (22).

m = me + m1
= Me + Wf + Wr
= Me + {Wf1 / (Vsf1-Vsf0)} (Vsf-Vsf0)
-{Wr1 / (Vsr1-Vsr0)} (Vsr-Vsr0) (22)
It should be noted that the kinetic energy Ei is substituted by substituting the corrected mass m obtained by the equation (22) into the equation (5), and the potential energy Ep is substituted according to the load amount by substituting into the equation (6). It can be calculated accurately.

  Therefore, according to the embodiment shown in FIG. 5, it is possible to calculate the energy consumption rate Ecj [kJ / m] shown in the equation (7) with a more accurate value.

DESCRIPTION OF SYMBOLS 10, 10A ... HEV vehicle 12 ... Engine 14 ... Driving motor 18 ... Fuel tank 20 ... Fuel injection device 22 ... Meter ECU (ECU)
24 ... Battery 28 ... Electric power sensor 30 ... Altitude sensor 32 ... Inclination sensor 34 ... Vehicle speed sensor 36 ... Distance sensor 40 ... Multi-information display (display)
52 ... Kinetic energy calculation means (Ei calculation means)
54... Position energy calculation means (Ep calculation means)
56: Electric energy calculation means (Eb calculation means)
58 ... Combustion energy calculation means (Ef calculation means)
60: Energy consumption rate calculating means (Ecj calculating means)
62 ... brake hydraulic pressure sensor 64 (64f, 64r) ... suspension sensor 66 ... road gradient calculating means 68 ... vehicle acceleration calculating means 70 ... corrected mass calculating means

Claims (8)

A motion efficiency determination device for determining the motion efficiency of a vehicle,
Vehicle speed detection means for detecting the speed of the vehicle;
Altitude detecting means for detecting the altitude of the road on which the vehicle travels;
Power detection means for detecting the power consumption of the traveling motor;
Kinetic energy calculating means for calculating kinetic energy according to the mass of the vehicle and the vehicle speed detected by the vehicle speed detecting means;
Positional energy calculation means for calculating potential energy according to the height detected by the height detection means;
Electrical energy calculation means for calculating electrical energy according to the power consumption detected by the power detection means;
Energy consumption rate calculating means,
The energy consumption rate calculating means includes:
An kinetic efficiency determination apparatus, wherein an energy consumption rate of the vehicle is obtained from the kinetic energy, the potential energy, and the electric energy. The exercise efficiency determination device according to claim 1,
further,
Fuel injection amount detection means for detecting the fuel injection amount;
Combustion energy calculation means for calculating combustion energy according to the fuel injection amount detected by the fuel injection amount detection means,
The energy consumption rate calculating means includes:
An kinetic efficiency determination apparatus characterized in that an energy consumption rate of the vehicle is obtained from energy obtained by adding the combustion energy to the kinetic energy, the potential energy, and the electric energy. In the exercise efficiency determination device according to claim 2,
further,
Providing travel distance detection means for detecting the travel distance of the vehicle,
When the vehicle is traveling, the energy consumption rate is obtained by dividing the sum of the combustion energy, the kinetic energy, the positional energy, and the electrical energy by the traveling distance detected by the traveling distance detecting means. When the vehicle is stopped, the motion efficiency determination device is calculated by dividing the sum of the combustion energy and the electric energy by the stop time. The apparatus for measuring exercise efficiency according to claim 3.
When the vehicle is stopped, when performing idle stop control, the energy consumption rate is calculated by dividing the electric energy value by the stop time. The exercise efficiency determination device according to claim 1,
When the vehicle is running, the energy consumption rate is calculated by dividing the sum of the kinetic energy, the positional energy, and the electrical energy by the travel distance detected by the travel distance detection means. When the vehicle is stopped, the value of the electric energy is calculated by dividing by the stop time. In any one of Claims 1-3, or the exercise efficiency determination apparatus of Claim 5,
The altitude detection means includes road gradient detection means for detecting a road gradient of a road on which the vehicle travels, and travel distance detection means for detecting a travel distance of the vehicle, and the road gradient; An exercise efficiency determination apparatus, wherein an altitude of a road on which the vehicle travels is detected according to the travel distance traveled on a road gradient. The exercise efficiency determination device according to claim 6,
Brake fluid pressure detecting means for detecting a brake fluid pressure at the time of braking operation of the vehicle;
Vehicle acceleration detecting means for detecting the acceleration of the vehicle,
The road efficiency detecting device detects the road gradient based on the brake fluid pressure and the acceleration. In the exercise efficiency determination device according to any one of claims 1 to 7,
A suspension stroke sensor for detecting vertical movement of the vehicle;
The kinetic energy or potential energy is determined at least according to the mass of the vehicle, and the mass of the vehicle is determined by the mass of the vehicle body, the load on the vehicle, and the output value of the suspension stroke sensor. A motion efficiency determination device characterized by being obtained.

Images