JP2018192951A - Method for estimating loading mass in vehicle - Google Patents

Abstract

To provide a method for estimating a loading mass in a vehicle, which makes it possible to eliminate, for example, an expensive gradient sensor by estimating a loading mass without receiving influence of a travel resistance torque.SOLUTION: A vehicle loading mass is estimated by calculating a resonance frequency by detecting, from engine speed information, resonance phenomenon that occurs in a drivetrain system at the timing of a sudden change in driving torque information in an engine being a driving source mounted on a vehicle, and by performing a comparison operation between the resonance frequency and a resonance frequency at each loading being previously stored in a computer.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for estimating a mass loaded on a vehicle using an engine as a drive source, and particularly includes an engine mounted on a vehicle during traveling without using a direct detection means such as a load meter. The present invention relates to a method for estimating a mass loaded on a vehicle using information detected from various traveling devices.

  In vehicles using an engine as a drive source, the load on the engine and the mass of the automatic transmission are affected by the load of the engine and the automatic transmission. Especially, in a large vehicle such as a truck with a large increase / decrease in the load mass, It is necessary to cope with changes in the loaded mass during traveling without using direct detection means. Conventionally, for example, an in-vehicle type that estimates the mass loaded on the vehicle based on the driving force or acceleration of the traveling vehicle, for example. An apparatus for estimating a loading mass is provided in JP-A-9-72776, JP-A-9-325065, JP-A 20001-304948, and the like.

  FIG. 11 shows an example of a conventional on-vehicle type loading mass estimation device, and a vehicle speed sensor 2a, an engine injection amount sensor 3a mounted on a vehicle as main input information to a loading amount calculation computer (CPU) 1a, The engine rotation sensor 4a, the accelerator pedal position sensor 5a, the clutch pedal position sensor 6a, the brake pedal position sensor 7a, the clutch engagement sensor 8a, the gear position sensor 9a, and the gradient sensor 10a are connected and calculated in the computer (CPU) 1a. The loaded mass information (mi) is output to the display 11a installed in the instrument panel of the driver's seat to provide information to the driver, or provided to another computer (not shown) to control the vehicle body. Useful for optimization.

  FIG. 12 explains the dynamic balance of the vehicle motion with respect to the detection principle in the conventional method for estimating the load mass, where m is the load mass, Te is the engine drive torque, Tr is the running resistance torque, and Vs is the vehicle speed. .

  FIG. 13 shows the change over time in the detection information when the accelerator is fully opened in the conventional method for estimating the load mass in FIG. 12, and the engine is driven at the same time as the accelerator is depressed by the accelerator information. When the torque (Te) increases and becomes larger than the running resistance torque (Tr), the vehicle body accelerates as an acceleration torque, and the vehicle speed (Vs) shown in FIG. 12 increases.

  When the loading mass is light, the inertia moment is small, so the vehicle speed increases rapidly. When the loading mass is heavy, the inertia moment is large, so the vehicle speed increases slowly. Therefore, it is possible to identify the loaded mass by detecting the acceleration (α) obtained by differentiating the vehicle speed (Vs) with respect to time.

  As shown in FIG. 14, the relationship between the acceleration torque (Te-Tr) and the acceleration (α) is a relationship indicating a constant acceleration (α) with respect to the acceleration torque (Te-Tr) if the loaded mass is a constant value. Therefore, α / (Te−Tr) is defined as an acceleration per unit acceleration torque with an index value, and the relationship between the index value and the load mass (m) is an inversely proportional correlation as shown in FIG. The loading mass (m) is detected from the relational expression.

  However, in actual vehicles, the running resistance torque (Tr) is not constant, and is actually changing depending on various disturbance factors.

  FIG. 16 illustrates the mechanical balance between the vehicle and the running torque during climbing, but the load (Fa) applied in the vertical direction from the tire center shifts to the vehicle rear side as the angle of the gradient sensor (θ) increases. Therefore, the load (Fb) that pulls the vehicle rearward is increased, which is one of the factors that increase the running resistance torque (Tr).

  FIG. 17 shows changes in the running resistance torque (Tr) when running on each gradient. Even if the engine driving torque is constant, the running resistance torque (Tr) changes greatly depending on the flat road, the uphill road, and the downhill road. As a result, the bearings and tires may be affected when the load mass (m) is simply increased even when the running resistance torque (Tr) at a constant flat road speed is obtained as shown in FIG. Therefore, there is a disturbance factor such as an overall increase in the running resistance torque (Tr).

  Thus, in order to realize the conventional load capacity detection technology, it is important to predict the running resistance torque (Tr) that changes in the actual environment, and in order to take this into account, the gradient sensor Compensating and calculating the running resistance torque (Tr) using the information (θ) is a general countermeasure technique as disclosed in, for example, Japanese Patent Laid-Open No. 6-201523.

  FIG. 19 shows an example of a control block diagram taking these into consideration. The flow of signals will be described in order. The fuel injection amount (Ti), the engine speed (Ne), the accelerator information (ACP), the brake information (BRKP) ) And the like, the torque generated in the engine is estimated, and the engine driving torque (Te) finally generated on the tire is calculated from the gear information (GEAR), the clutch information (CLP), and the like.

  Next, the travel resistance torque (Tr) generated in the vehicle at this time is calculated from the gradient sensor (θ) information and the vehicle speed (Vs), gear information (GEAR), clutch information (CLP), etc. Is calculated by calculating the acceleration torque (Te-Tr), the vehicle speed (Vs) is differentiated to calculate the acceleration (α), and the acceleration torque (Te-Tr) described above is calculated. By dividing, the acceleration per unit acceleration torque (α / (Te−Tr)) is calculated.

  Here, a predicted load mass (m) is defined in advance in the data provided for each gear, and this data is linearly interpolated from the acceleration per unit acceleration torque (α / (Te−Tr)) described above. Thus, the loading mass (m) is calculated. Further, in order to improve the accuracy of the load mass (m), a condition for stabilizing the data is determined in advance from information such as the accelerator information (ACP) and the engine speed (Ne). The load mass (m) is estimated and calculated by starting the calculation processing of the load mass estimation.

  However, in the conventional method of estimating the load mass based on the relationship between the speed (Vs) and the acceleration torque, the running resistance may be changed under various environmental conditions, and thus the running resistance is correctly estimated. In particular, the information of the gradient sensor is essential, and there is a problem that the cost increases by attaching this gradient sensor (θ).

JP-A-9-72776 JP-A-9-325065 JP 20001-304948 A JP-A-6-201523

  The present invention has been made paying attention to the above-mentioned conventional problems, and is capable of eliminating an expensive gradient sensor or the like by estimating the loaded mass without being affected by the running resistance torque. It is an object of the present invention to provide an estimation method.

  In order to solve the above-described problems, the vehicle load mass estimation method according to the present invention is a resonance phenomenon that occurs in the drive train system at the timing when drive torque information in an engine that is a drive source mounted on the vehicle changes suddenly. Is detected from the engine rotational speed information, the resonance frequency is obtained, and the resonance frequency is compared with the resonance frequency at each loading amount stored in advance in the computer to estimate the vehicle loading mass. .

  In the present invention, the resonance frequency can be corrected using gear information currently used detected from a transmission installed in the vehicle.

  In addition, the present invention provides at least one of the brake information detected from the operation of the brake device installed in the vehicle and the clutch device information detected from the operation of the clutch device. It is possible to increase the accuracy of the load mass by increasing the number of comparison calculations of the load mass detection by grasping the resonance phenomenon that appears when the torque suddenly changes.

  Further, in the present invention, the currently used gear information detected from the transmission is the neutral position or the clutch device information detected from the operation of the clutch device is the clutch non-engagement position, and the engine is driven. However, when the travel stop detection information is detected, the load mass of the currently used gear information or the connected clutch device information until the next drive gear information or the connected clutch device information is detected. It is possible to improve the detection accuracy of the loaded mass by temporarily stopping the comparison operation and retaining the original loaded mass information.

  Furthermore, in the present invention, when the vehicle travels with a constant load amount during a predetermined travel period, the comparison operation is continuously started and averaged except when the vehicle is stopped for a predetermined time or more in the predetermined travel period. It is also possible to improve the detection accuracy of the resonance frequency by making a comprehensive determination using processing.

  In the present invention, when it is detected from the driving torque information that the engine has been stopped (key-off) or stopped running for a certain time or longer, the information on the loaded weight calculated by the comparison is reset to an initial value. By erasing the resonance frequency, the resonance frequency can be detected quickly and reliably without being affected by the original resonance frequency when stopping and reloading the load.

  Further, in the present invention, the information on the load mass is provided to the driver by providing means for notifying the driver of the estimated load mass using an instrument panel display or a device equivalent thereto. Thus, the driver can perform an appropriate safe and energy-saving operation according to the loaded mass.

  Furthermore, in the present invention, after the information on the estimated load mass is determined, the information on the load mass is used to control the engine such as the fuel injection amount of the engine or the intake air amount throttle valve (throttle valve). By correcting the device, it is possible to improve the stability and drivability of the vehicle.

  According to the present invention, it is needless to say that the load mass can be detected and estimated during traveling without actually using a weighing device, and without being affected by the traveling resistance torque as compared with the conventional estimation device of this type. It is possible to provide an apparatus for estimating a loading mass in a vehicle that can eliminate an expensive gradient sensor by estimating the loading mass.

1 is a block circuit diagram of a loaded mass detector system used in a preferred embodiment of the present invention. FIG. 2 is a diagram illustrating the principle of a method for estimating a load using the load mass detection apparatus shown in FIG. 1 and a drive train constituting a vehicle body that is modeled with the vehicle body regarded as a rotating body. FIG. 3 is a diagram showing the relationship between the frequency and the rotational fluctuation (amplitude) of the resonance frequency of the drive train shown in FIG. 2 and the drive train in which the drive train shown in FIG. 2 is regarded as a rotating body with one degree of freedom. FIG. 3 is a relationship diagram between the resonance frequency (ωc) and the moment of inertia (Im) corresponding to the loaded mass in the present embodiment shown in FIG. 1. Description of load mass estimation when carrying out the embodiment shown in FIG. The control block diagram of the estimation method determination process of the loading mass for implementing embodiment shown in FIG. The time series data of the engine speed at the time of acceleration about the actual example of the vehicle amount estimation determination for implementing embodiment shown in FIG. Frequency analysis data of engine rotation speed at the time of second gear acceleration for an example for carrying out the embodiment shown in FIG. Frequency analysis data of engine rotation speed at the time of third gear acceleration for an example for carrying out the embodiment shown in FIG. Frequency analysis data of engine rotation speed at the time of 4-speed gear acceleration for an example for carrying out the embodiment shown in FIG. The block diagram which shows an example of the detection apparatus system used for the estimation method of the conventional loading mass. Explanatory drawing which shows the detection principle of the loading mass (m) in the conventional estimation method of a loading mass. Explanatory drawing which shows the time change of detection information, such as an engine drive torque (Te) about the detection information when it accelerates by the accelerator full open in the conventional loading mass estimation method. The relationship figure of the acceleration ((alpha)), driving | running | working resistance torque (Tr), and engine drive torque (Te) in the conventional load mass estimation method. The relationship figure of the acceleration (alpha) per unit acceleration torque and loading mass (m) in the conventional estimation method of loading mass. Explanatory drawing about the driving | running | working resistance torque (Tr) in the estimation method of the conventional loading mass. The related figure of each gradient and running resistance torque (Tr) in the conventional loading mass estimating method. FIG. 6 is a relationship diagram between a running resistance torque (Tr) and a vehicle speed (Vs) at a constant flat road speed in a conventional loading mass estimation method. The control block diagram which shows an example of the loading amount estimation determination process in the conventional loading mass estimation method.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an example of an estimation device for carrying out a preferred embodiment of the present invention. Basically, an example of a conventional vehicle-mounted load mass estimation device shown in FIG. Similarly, a computer (CPU) 1 for calculating a load amount has a vehicle speed sensor 2, an engine injection amount sensor 3, an engine rotation sensor 4, an accelerator pedal position sensor 5, a clutch pedal position sensor 6, and the like as main input information. A brake pedal position sensor 7, a clutch engagement sensor 8, and a gear position sensor 9 are connected, and the load mass information (mi) calculated in the computer (CPU) 1 is displayed on a display 11 installed on the instrument panel of the driver's seat. To provide information to the driver and to provide information to another computer (not shown), which can be used for optimization of vehicle control. In that in this embodiment does not have a gradient sensor of the conventional example shown in FIG 11 (theta) is different.

  FIG. 2 shows the principle of detection in the estimation method of the loaded mass of the estimation apparatus used in the embodiment of the present invention in the present embodiment, and constitutes a vehicle body that is modeled by considering all the dynamic balance of the vehicle motion as a rotating body. This is shown together with the drive train 12, where m is the load mass, Te is the engine driving torque, Tr is the running resistance torque, and Vs is the vehicle speed.

The drive train 12 is a rotating body 13 having a relatively light moment of inertia (Im ₀ ), and an engine driving torque (Te) is generated from the rotating body 13. A rotating body 14 having a moment of inertia corresponding to the mass (m) is rotated, and a rotating body 15 constituting a vehicle body such as a tire is rotated as a relatively light inertia moment (Im ₁ ) with respect to the loaded mass. At this end, the running resistance torque (Tr) is generated to become the resistance of the engine driving torque.

  The engine rotor 13 and the other rotors 14 and 15 are connected by a rotor 16 such as a propeller shaft or a clutch spring having relatively low rigidity.

  Here, as the moment of inertia (Im) that affects the entire rotating body, the rotating body 14 related to the load mass (m) is the largest, and therefore the engine and other rotating bodies 13 and 15 are integrated into one. When defined as a rotating body 12 having a degree of freedom, it can be considered as a rotating body 17 having a certain resonance frequency (ωc) as shown in FIG.

Furthermore, the resonance frequency (ωc) depends on the spring component (k ₁ ) and the moment of inertia component (Im) of the system, and the spring component (k ₁ ) is determined by the specifications of the drive train system and the gear reduction ratio. This resonance frequency (ωc) varies depending on the moment of inertia component (Im) due to the loaded mass (m).

  Further, as shown in FIG. 4, the resonance frequency (ωc) and the loading mass (m) are the same as the loading mass (m) if the inertia moment (Im) corresponding to the loading mass (m) is constant. Since there is a certain relationship, the relationship between the resonance frequency (ωc) and the loaded mass (m) shows an inversely proportional relationship.

  In the present invention, the loaded mass (m) is estimated from the information of the resonance frequency (ωc) using the above-described principle.

  FIG. 5 shows an example of a resonance phenomenon of the engine rotational speed that occurs in the vehicle when accelerating. The engine torque (Te [Nm]) is applied to the rotating body along with the acceleration, and the engine rotational speed is correspondingly applied thereto. It is confirmed that the resonance phenomenon appears.

  When the loaded mass (m) is small, the engine speed (Ne [rpm]) has a relatively high frequency fluctuation (A), and this fluctuation changes to a low frequency as the mass increases (B) (C ). This variation occurs both in the direction of applying torque and in the opposite direction of decreasing torque, and the frequency depends on the spring constant and moment of inertia of the system, and is not affected by the running resistance torque. For this reason, it is not necessary to estimate the running resistance torque as used in the conventional method, and it is not affected by the gradient, so that the robustness is high.

  FIG. 6 shows an example of an embodiment of a control block diagram of a determination process for implementing the load mass estimation method according to the present invention, and is an engine drive torque estimation calculation process that is a part of the process for estimating and calculating the engine torque. Is the same as the conventional method.

  When the engine driving torque (Te) information, information from the gear engagement and gear speed determination, accelerator information (ACP), etc. are used to determine conditions suitable for the load mass estimation in the start determination process, and when these conditions are satisfied Using the resonance frequency information (ωc), the loaded mass is calculated by the loaded mass estimation calculation processing unit.

  For the information on the resonance frequency (ωc), the engine speed (Ne) is subjected to fast Fourier transform (FFT), and the resonance frequency (ωc) is detected from the peak frequency. Since the relationship between the loaded mass and the moment of inertia seen from the engine rotation side changes depending on the gear reduction ratio, table data with different mass data is prepared for each gear information (GEAR), and linear interpolation is referred to. The conversion processing from ωc) to the loading mass (m) is performed to estimate the loading mass.

  FIG. 7 shows the result of the processing for estimating the loading mass according to the embodiment of the present invention. The graph shown above shows the engine speed (Ne) and the vehicle speed (Vs) when the vehicle is empty (the loading mass is 0). A time series is shown, and fluctuations in the engine speed appear during acceleration after shifting. The graph shown below shows the time series of engine speed (Ne) and vehicle speed (Vs) when acceleration under the same conditions as the graph shown above is performed with a loading mass of 25 t added. Thus, it can be confirmed that a rotational fluctuation of a frequency different from the rotational fluctuation at the time of the empty vehicle shown above appears in the same acceleration portion.

  FIGS. 8 to 10 show the results of FFT analysis of the engine speed fluctuation component at the acceleration points of the second gear, the third gear, and the fourth gear, respectively. The peak at 3.1 Hz is shown in (a), whereas the peak is 1.6 Hz in the 25-ton load state (b), and the peak is 2.7 Hz in the empty state (a) at the acceleration point of the third gear. In contrast, a peak of 1.6 Hz is shown in the loaded state (b) of 25 t, and a peak of 3.1 Hz is shown in the empty state (a) at the acceleration point of the 4-speed gear, It can be confirmed that the frequency in the loaded state is lowered to 1.6 Hz in the loaded state (b) of 25 t.

  In this way, the load mass (m) can be estimated by comparing and calculating the relationship between the resonance frequency (ωc) and the load mass (m) by referring to the table data stored in advance in the storage device of the computer. It is possible to detect the information of the resonance frequency by frequency analysis of the fluctuation of the engine rotation speed that occurs when the engine torque changes suddenly, such as sudden acceleration and sudden deceleration, and the vehicle is detected from this frequency information and gear information. In particular, it is possible to estimate the load mass without being affected by the running resistance torque, and the gradient sensor or the like can be eliminated.

  Furthermore, as shown in FIG. 8 to FIG. 10, the present invention differs in the numerical value of each frequency by changing the gear of the transmission being used, and at the present time detected from the transmission installed in the vehicle. A more accurate load mass can be estimated by correcting the resonance frequency using the gear information of the transmission gear used.

  In addition, the present invention provides at least one of the brake information detected from the operation of the brake device installed in the vehicle and the clutch device information detected from the operation of the clutch device. It is possible to increase the accuracy of the load mass by increasing the number of comparison calculations of the load mass detection by grasping the resonance phenomenon that appears when the torque suddenly changes.

  Further, in the present invention, the currently used gear information detected from the transmission is the neutral position or the clutch device information detected from the operation of the clutch device is the clutch non-engagement position, and the engine is driven. However, if the travel stop detection information is detected, the load mass comparison calculation is performed until the gear information currently used is detected until the next drive gear information or the connected clutch device information is detected. Is temporarily stopped and the original loading mass information is retained, so that the detection accuracy of the loading mass can be improved.

  Furthermore, in the present invention, when the vehicle travels with a constant load amount during a predetermined travel period, the comparison operation is continuously started and averaged except when the vehicle is stopped for a predetermined time or more in the predetermined travel period. It is also possible to improve the detection accuracy of the resonance frequency by making a comprehensive determination using processing.

  In addition, in the present invention, when the driving torque information detects that the engine is in an engine stopped (key-off) state or stopped running for a certain period of time, the comparison information of the loaded mass is reset to an initial value. By erasing the original resonance frequency, the resonance frequency can be detected quickly and reliably without being affected by the original resonance frequency when stopping and reloading the load.

  In the present invention, the information on the loaded mass is provided to the driver by providing means for notifying the driver by using the indicator 11 installed on the instrument panel of the driver's seat using the estimated information on the loaded mass. Thus, the driver can perform an appropriate safe and energy-saving operation according to the loaded mass.

  Furthermore, in the present invention, after the information on the estimated load mass is determined, the information on the load mass is used to control the engine such as the fuel injection amount of the engine or the intake air amount throttle valve (throttle valve). By correcting the device, it is possible to improve the stability and drivability of the vehicle.

  1 Computer (CPU), 2 vehicle speed sensor, 3 engine injection amount sensor, 4 engine rotation sensor, 5 accelerator pedal position sensor, 6 latch pedal position sensor, 7 brake pedal position sensor, 8 clutch engagement sensor, 9 gear position sensor, 11 Display, 12 drive train, 13, 14, 15, 16, 17 Rotating body

Claims (8)

  A resonance phenomenon occurring in the drive train system is detected from the engine rotational speed information at the timing when the drive torque information in the engine which is a drive source mounted on the vehicle suddenly changes, and the resonance frequency is obtained in advance in the computer. A method for estimating a loading mass in a vehicle, wherein the vehicle loading mass is estimated by comparing with a stored resonance frequency at each loading amount.   2. The method for estimating a loading mass in a vehicle according to claim 1, wherein the resonance frequency is corrected using gear information currently used detected from a transmission installed in the vehicle.   The torque suddenly changes from at least one of brake information detected from the operation of the brake device installed in the vehicle or clutch device information detected from the operation of the clutch device at the timing of sudden change of the driving torque information of the engine 3. The method of estimating a loading mass in a vehicle according to claim 1, wherein the accuracy of the loading mass is improved by increasing the number of comparison operations of the loading mass detection by capturing a resonance phenomenon that sometimes appears.   Although the currently used gear information detected from the transmission is in the neutral position or the clutch device information detected from the operation of the clutch device is in the clutch non-engaged position and the engine is driven, the vehicle stops running. When the detection information is detected, the load mass comparison calculation based on the currently used gear information or the connected clutch device information is temporarily performed until the next drive gear information or the connected clutch device information is detected. 4. The method for estimating a loading mass in a vehicle according to claim 1, wherein the detection accuracy of the loading mass is improved by stopping and retaining the original loading mass information.   When the vehicle travels with a certain load amount during a predetermined travel period, the comparison calculation is started continuously except when the vehicle is stopped for a predetermined time or longer in the predetermined travel period, and is comprehensively calculated using an averaging process. 5. The method for estimating a loading mass in a vehicle according to claim 1, wherein the detection accuracy of the resonance frequency is improved by the determination.   When the driving torque information detects that the engine is stopped (key-off) or stopped running for a certain time or longer, the comparison information of the loaded mass is reset to the initial value and the original resonance frequency is deleted. The resonance frequency can be detected quickly and reliably without being affected by the original resonance frequency when the vehicle is stopped and reloaded. 6. A method for estimating a loading mass in a vehicle according to 4 or 5.   The information on the loaded mass is provided to the driver by providing means for notifying the driver of the information using the instrument panel display or the equipment equivalent thereto using the estimated information on the loaded mass. Item 7. A method for estimating a loaded mass in a vehicle according to item 1, 2, 3, 4, 5, or 6. After the information on the estimated load mass is confirmed, the information on the load mass is used to correct the engine control device such as the fuel injection amount of the engine or the intake air amount throttle valve (throttle valve). The method for estimating a loading mass in a vehicle according to claim 1, 2, 3, 4, 5, 6 or 7, which is useful for improving the stability and drivability of the vehicle.

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