JP2018179543A - Estimation device and estimation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an estimation device and an estimation method which effectively improve the accuracy of estimating the weight of a vehicle.SOLUTION: An estimation device includes: a determination section 110 for determining whether or not a vehicle 1 which travels on an uphill road at a constant speed is in a state of constant-speed travelling on an uphill road on the basis of a vehicle speed V and an angle value θ; a drive force estimation section 120 for estimating drive force F of the vehicle 1 on the basis of output torque of an engine 10; and a vehicle weight estimation section 130 for estimating vehicle weight W of the vehicle 1 on the basis of the vehicle speed V, the angle value θ, and the drive force F, when the state of constant-speed travelling on an uphill road is determined.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an estimation apparatus and estimation method, and more particularly to estimation of vehicle weight.

  Heretofore, various techniques have been proposed for estimating the weight of a vehicle based on traveling state quantities during acceleration traveling, such as acceleration and driving force of the vehicle, as this type of estimation device (see, for example, Patent Documents 1 to 3) ).

JP, 2012-181047, A JP, 2010-243305, A JP, 2013-154684, A

  In general, at the time of traveling of a vehicle, the ratio of constant speed traveling tends to be larger than the ratio of accelerated traveling. For this reason, in the estimation method using acceleration as in the above-described conventional technique, there is a problem that the time when the vehicle weight can be estimated is limited only to the time of acceleration traveling with a small percentage. In addition, since the behavior of the vehicle is not stable during acceleration, there is a possibility that sufficient estimation accuracy can not be secured by the estimation method based on the traveling state quantity during acceleration. In addition, since the acceleration sensor is essential, there is also a problem that the cost increases due to the increase in the number of sensors.

  The technique of the present disclosure aims to effectively improve the estimation accuracy of the vehicle weight.

  The apparatus of the present disclosure acquires vehicle speed acquisition means for acquiring the vehicle speed of a vehicle, inclination angle acquisition means for acquiring an inclination angle of the vehicle in the front-rear direction with respect to the horizontal direction, and output torque of a drive source mounted on the vehicle In the uphill traveling state where the vehicle travels at a constant speed on the uphill road based on the output torque acquiring means, the vehicle speed acquired by the vehicle speed acquiring means, and the inclination angle acquired by the inclination angle acquiring means A driving force estimating means for estimating the driving force of the vehicle based on the determining means for determining whether there is any, the driving force of the vehicle based on the output torque acquired by the output torque acquiring means; Based on the vehicle speed acquired by the vehicle speed acquisition unit, the inclination angle acquired by the inclination angle acquisition unit, and the driving force estimated by the driving force estimation unit. There are, characterized in that it comprises, a vehicle weight estimation means for estimating the vehicle weight of the vehicle.

Further, the vehicle weight estimation means may set the vehicle weight as follows: W = (F−μa · A · V ² ) / (μr + g · sin θ), where W: vehicle weight, F: driving force, μr: rolling resistance coefficient It is preferable to obtain | require from μa: air resistance coefficient, A: vehicle front projection area, V: vehicle speed, g: gravitational acceleration.

  In the vehicle, motive power from the drive source is transmitted from the transmission to the drive wheels through the differential gear, and the drive force estimation means determines the gear ratio of the transmission to the output torque acquired by the output torque acquisition means. Preferably, the driving force is estimated by dividing the value obtained by multiplying the final gear ratio of the differential gear by the wheel diameter of the driving wheel.

  Further, in the determination means, the inclination angle acquired by the inclination angle acquisition means is greater than 0, the vehicle speed acquired by the vehicle speed acquisition means is greater than 0, and the vehicle speed acquired by the vehicle speed acquisition means It is preferable to determine that the vehicle is traveling at a constant speed on a slope when the vehicle speed change amount obtained from the vehicle speed is equal to or less than a predetermined threshold value.

  The method of the present disclosure determines whether or not the vehicle is traveling at a constant speed on an uphill road traveling at a constant speed on an uphill road based on the vehicle speed of the vehicle and the inclination angle of the vehicle in the front-rear direction with respect to the horizontal direction. When it is determined that the vehicle is traveling uphill, the vehicle speed obtained from the vehicle speed of the vehicle, the inclination angle in the front-rear direction of the vehicle with respect to the horizontal direction, and the output torque of the drive source mounted on the vehicle The vehicle weight of the vehicle is estimated based on the force.

  According to the technology of the present disclosure, the estimation accuracy of the vehicle weight can be effectively improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a typical whole block diagram which shows the vehicle which concerns on one Embodiment of this invention. It is a functional block diagram showing an estimation device concerning one embodiment of the present invention. It is a flowchart explaining the estimation process of the vehicle weight which concerns on one Embodiment of this invention. It is a schematic diagram explaining the balance component at the time of uphill driving | running | working of a vehicle at a fixed speed.

  Hereinafter, an estimation apparatus and an estimation method according to an embodiment of the present invention will be described based on the attached drawings. The same parts are given the same reference numerals, and their names and functions are also the same. Therefore, detailed description about them will not be repeated.

  FIG. 1 is a schematic overall configuration diagram showing a vehicle 1 according to the present embodiment. An engine 10 is mounted on the vehicle 1 as an example of a drive source. A transmission 12 is connected to the engine 10 via a clutch device 11. Left and right drive wheels (left and right rear wheels) 16L and R are connected to the transmission 12 via the propeller shaft 13, the differential gear 14 and the left and right drive shafts 15L and R, respectively. The vehicle 1 is also provided with left and right steered wheels (left and right front wheels) 17L and R, various sensors 20 to 24, an electronic control unit 100 (hereinafter referred to as an ECU), and the like.

  The engine rotational speed sensor 20 (an example of an output torque acquisition unit) acquires an engine rotational speed Ne from a crankshaft (not shown) of the engine 10. The accelerator opening degree sensor 21 (an example of an output torque acquisition means) acquires the fuel injection amount Q of the engine 10 from the depression amount of the accelerator pedal (not shown). The vehicle speed sensor 22 (an example of a vehicle speed acquisition unit) acquires the vehicle speed V of the vehicle 1 from an output shaft (not shown) of the propeller shaft 13 or the transmission 12. The inclination sensor 23 (an example of an inclination angle acquisition unit) acquires an inclination angle θ of the vehicle 1 with respect to the horizontal direction. The shift position sensor 24 obtains the current shift position SP of the transmission 12. The sensor values of the various sensors 20 to 24 are input to the electrically connected ECU 100.

  The ECU 100 performs various controls of the vehicle 1 and includes a known CPU, ROM, RAM, input port, output port, and the like.

  Further, as shown in FIG. 2, the ECU 100 has a traveling state determination unit 110, a driving force estimation unit 120, and a vehicle weight estimation unit 130 as a part of functional elements. Although each of these functional elements is described as being included in the ECU 100 which is an integral hardware, any part of these may be provided in a separate hardware.

  The traveling state determination unit 110 is an example of the determination unit of the present invention, and determines the uphill road of the vehicle 1 based on the vehicle speed V input from the vehicle speed sensor 22 and the inclination angle θ input from the inclination sensor 23. It is determined whether or not the vehicle is in the "uphill road constant speed traveling state" where the vehicle travels at high speed. More specifically, the traveling state determination unit 110 determines that the inclination angle θ is larger than 0 (zero) (θ> 0) when the vehicle 1 is traveling (V> 0) where the vehicle speed V is larger than 0 (zero). If the vehicle speed change amount ΔV (for example, the change amount per unit time) obtained by differentiating the vehicle speed V is equal to or less than a predetermined threshold value, the vehicle 1 is determined to be in the “uphill steady travel state”.

  The driving force estimation unit 120 is an example of the driving force estimation means of the present invention, and estimates the driving force F of the vehicle 1 according to the following equation (1).

F = k 1 · (Te · it · if) / Rw (1)
However, Te: engine torque (N · m)
it: Transmission gear ratio
if: Final gear ratio
Rw: Wheel diameter (m)
k1: coefficient The engine torque Te is a torque map (not shown) defining the relationship between the engine speed Ne and the fuel injection amount Q stored in advance in the memory of the ECU 100, the engine speed sensor 20 and the accelerator opening sensor 21. It is calculated by referring to the sensor value of.

  The transmission gear ratio it is set by reading the gear ratio of each gear of the transmission 12 (see FIG. 1) stored in advance in the memory of the ECU 100 according to the sensor value of the shift position sensor 24. When the clutch device 11 (see FIG. 1) is connected, the transmission gear ratio it is determined from the sensor value (input speed) of the engine speed sensor 20 and the sensor value (output speed) of the vehicle speed sensor 22. It may be calculated.

  The final gear ratio if is a gear ratio between the drive gear of the differential gear 14 (see FIG. 1) and the ring gear, and is preset as a value unique to the vehicle 1. The wheel diameter Rw is an outer diameter of the left and right drive wheels 16L and 16R (see FIG. 1), and is preset as a value unique to the vehicle 1. Similarly, the coefficient k1 is also preset as a value unique to the vehicle 1.

  The vehicle weight estimation unit 130 is an example of the vehicle weight estimation unit of the present invention, and calculates the vehicle weight W when the traveling state determination unit 110 determines that the vehicle 1 is in the “slope speed road constant traveling state”. More specifically, the equation of motion of each balance component (see FIG. 4) when the vehicle 1 travels at a constant speed on the uphill road is expressed by the following equation (2).

F = μr · W + μa · A · V ² + W · g · sin θ (2)
However, F: Driving force of the vehicle 1 (N)
W: Weight of vehicle 1 (kg)
V: Vehicle speed of vehicle 1 (m / s)
θ: inclination angle (deg) of vehicle 1 in the front-rear direction
g: Gravity acceleration (m / s ² )
A: Projected area on front of the vehicle (m ² )
μr: rolling resistance coefficient
μa: Air resistance coefficient In Equation (2), the rolling resistance coefficient μr, the air resistance coefficient μa, and the vehicle front projection area A are preset as values unique to the vehicle 1. If equation (2) is solved for the vehicle weight W, the following equation (3) is obtained.

W = (F−μa · A · V ² ) / (μr + g · sin θ) (3)
The vehicle weight calculation unit 130 receives the driving force F input from the driving force estimation unit 120 and the vehicle speed sensor 22 when the traveling state determination unit 110 determines that the vehicle 1 is in the “uphill steady state traveling state”. The vehicle weight W is calculated by substituting the vehicle speed V and the inclination angle θ input from the inclination sensor 23 into the above equation (3). The calculated vehicle weight W is displayed on a display 80 provided in a driver's cab or the like (not shown) of the vehicle 1.

  Next, estimation processing of the vehicle weight W performed by the ECU 100 will be described based on a flowchart shown in FIG. The present control is started when the vehicle 1 is started (for example, when the ignition key is turned on of the engine 10), and is repeatedly executed at predetermined time intervals.

  In step S100, it is determined based on the sensor value of the vehicle speed sensor 22 whether or not the vehicle speed V is traveling greater than 0 (zero). If the vehicle speed V is traveling greater than 0 (zero) (affirmative), the present control proceeds to step S110. On the other hand, if the determination is negative, that is, if the vehicle speed V is at a stop (zero), the present control is returned.

  In step S110, based on the sensor value of the inclination sensor 23, it is determined whether or not traveling on an uphill road where the inclination angle θ is larger than 0 (zero). If the inclination angle θ is larger than 0 (zero) while traveling uphill (affirming), the present control proceeds to step S120. On the other hand, in the case of no, that is, when traveling on a flat road where the inclination angle θ is zero (0), this control is returned.

  In step S120, it is determined based on the sensor value of the vehicle speed sensor 22 whether or not the vehicle is traveling at a constant speed such that the vehicle speed change amount ΔV obtained by differentiating the vehicle speed V is less than a predetermined threshold. If the vehicle is traveling at a constant speed such that the vehicle speed change amount ΔV is less than or equal to the predetermined threshold (positive), the present control proceeds to step S130. On the other hand, in the case of no, that is, during acceleration traveling (or deceleration traveling) in which the vehicle speed change amount ΔV is larger than the predetermined threshold value, the present control is returned.

  In steps S130 to S150, a vehicle weight calculation process is performed. That is, in step S130, engine torque Te determined from each sensor value of engine speed sensor 20 and accelerator opening sensor 21, transmission gear ratio it determined from the sensor value of shift position sensor 24, and various constants set in advance The driving force F of the vehicle 1 is calculated by substituting the above equation (1).

  Next, in step S140, the driving force F calculated in step S130, the vehicle speed V input from the vehicle speed sensor 22, the inclination angle θ input from the inclination sensor 23, various constants set in advance, etc. By substituting it into 3), the vehicle weight W is calculated, and the calculated value of the vehicle weight is set to the calculated value of the vehicle weight W (n) as the current (n-th) vehicle weight.

  Next, in step S150, an averaging process of the calculated vehicle weight calculation value W (n) is performed. The averaging process is performed, for example, by integrating the first to n-th calculated vehicle weight values W (1) to W (n) and dividing by the number of operations n to obtain the average value W of vehicle weights up to the n-th n) Calculate mean. Specifically, for example, the previous ((n-1) th) vehicle weight average value W (n-1) mean and the vehicle weight calculation value W (n) calculated this time are expressed by the following equation (4) By substituting, the vehicle weight average value W (n) mean is determined up to n times. In addition, after calculating the vehicle weight average value W (n) mean, the vehicle weight average value W (n) mean calculated this time is prepared as the vehicle weight average value W (n-1) in preparation for the next average value calculation. Set to mean.

W (n) mean = (W (n) + W (n-1) mean (n-1)) / n (4)
By this averaging process, the variation in the vehicle weight average value W (n) mean is reduced, and the vehicle weight average value W (n) mean is updated for each calculation cycle.

  The averaging process of the vehicle weight is not limited to the simple addition and averaging of the first to n-th calculated values as in the above equation (4), for example, as shown in the following equation (5), The current calculation result W (n) may be multiplied by the weighting factor k, and the average value W (n-1) mean up to the previous round may be multiplied by the weighting factor (1-k) and added for averaging.

W (n) mean = k · W n + (1-k) W (n-1) mean (5)
In this case, the current (n-th) calculation result can be weighted and reflected on the average value up to the previous time.

  In step S160, the vehicle weight average value W (n) mean is displayed on the display 80 as an estimated value of the vehicle weight W, and then this control is returned.

  As described above in detail, according to the estimation device and estimation method of the present embodiment, when the vehicle 1 travels at a constant speed on the uphill road, the driving force F of the vehicle 1, the vehicle speed V, and the inclination angle θ are acquired Since the vehicle weight W is estimated based on the above equation (3), the vehicle weight W can be accurately estimated without being affected by the acceleration or the like applied to the vehicle 1 as compared with the prior art in which the weight is estimated during acceleration traveling. Becomes possible.

  Further, by estimating the vehicle weight W at the time of constant speed traveling having a ratio higher than acceleration traveling in vehicle traveling, it is possible to increase the frequency of execution of vehicle weight calculation processing, and estimation accuracy can be effectively improved. .

  In addition, an acceleration sensor is not required for estimation of the vehicle weight W, and cost increase due to an increase in the number of sensors and complication of arithmetic processing can be effectively prevented.

  The present invention is not limited to the embodiments described above, and can be appropriately modified and implemented without departing from the spirit of the present invention.

  For example, in the above embodiment, the vehicle 1 has been described as including the engine 10 as a drive source, but may be a hybrid vehicle or the like including a traveling motor.

Reference Signs List 1 vehicle 10 engine 11 clutch device 12 transmission 13 propeller shaft 14 differential gear 15L, R left and right drive shaft 16L, R left and right drive wheels (left and right rear wheels)
20 Engine Speed Sensor 21 Accelerator Opening Sensor 22 Vehicle Speed Sensor 23 Inclination Sensor 100 ECU
110 driving condition determination unit 120 driving force estimation unit 130 vehicle weight estimation unit

Claims (5)

Vehicle speed acquisition means for acquiring the vehicle speed of the vehicle;
Inclination angle acquisition means for acquiring an inclination angle of the vehicle in the longitudinal direction with respect to the horizontal direction;
An output torque acquiring unit that acquires an output torque of a drive source mounted on the vehicle;
Based on the vehicle speed acquired by the vehicle speed acquisition means and the inclination angle acquired by the inclination angle acquisition means, it is determined whether or not the vehicle is traveling at a constant speed on an uphill road traveling at a constant speed on an uphill road. Determination means,
Driving force estimation means for estimating the driving force of the vehicle based on the output torque acquired by the output torque acquisition means;
The vehicle speed acquired by the vehicle speed acquisition unit, the inclination angle acquired by the inclination angle acquisition unit, and the drive estimated by the driving force estimation unit when it is determined by the determination unit that the vehicle is in the uphill road constant speed traveling state Vehicle weight estimating means for estimating a vehicle weight of the vehicle based on a force. The vehicle weight estimation means sets the vehicle weight W = (F−μa · A · V ² ) / (μr + g · sin θ)
However, W: Vehicle weight F: Driving force μr: Rolling resistance coefficient μa: Air resistance coefficient A: Vehicle front projection area V: Vehicle speed g: Gravity acceleration The estimation device according to claim 1. In the vehicle, power from the drive source is transmitted from a transmission to a drive wheel via a differential gear.
The driving force estimating means divides a value obtained by multiplying the output torque acquired by the output torque acquiring means by the gear ratio of the transmission and the final gear ratio of the differential gear by the wheel diameter of the driving wheel. The estimation device according to claim 1 or 2, wherein the driving force is estimated. The determination unit is obtained from the vehicle speed acquired by the vehicle speed acquisition unit, and the inclination angle acquired by the inclination angle acquisition unit is larger than zero, and the vehicle speed acquired by the vehicle speed acquisition unit is larger than zero. The estimation device according to any one of claims 1 to 3, wherein when the amount of change in vehicle speed is equal to or less than a predetermined threshold value, it is determined that the vehicle is traveling on a slope constant speed. Based on the vehicle speed of the vehicle and the inclination angle of the longitudinal direction of the vehicle with respect to the horizontal direction, it is determined whether or not the vehicle is traveling at a constant speed on a slope. When it is determined that the vehicle is in the state, the vehicle speed of the vehicle, the inclination angle in the front-rear direction of the vehicle with respect to the horizontal direction, and the driving force of the vehicle obtained from the output torque of the driving source mounted on the vehicle Estimating the weight of a vehicle.

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