JP2005020831A - Driving force controller at level difference passing time by electric motor vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a longitudinal vibration of a vehicle body generated when wheels of an electric vehicle pass a road surface level difference. <P>SOLUTION: A driving force controller at the level difference passing time by a motor vehicle detects the change of a wheel speed of wheels at a stage in which the wheel starts contact with a road surface level difference, by utilizing excellent response of a motor estimated as 100 Hz or more when the wheels ride beyond the road surface level difference, and corrects to increase or decrease the drive force of the wheels so as to suppress the change of the wheel speed thereafter based on the detected data. Thus, the change of the wheel speed is suppressed to reduce the longitudinal vibration of the vehicle body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention takes advantage of the high responsiveness of an electric motor and, when a wheel passes a road surface step, instantaneously increases / decreases the driving force of the wheel to reduce the longitudinal vibration on the vehicle body side when the road surface step passes. It is about.
[0002]
[Prior art]
According to the description of Non-Patent Document 1, it is known that the responsiveness of an industrial electric motor is generally 100 Hz or higher, and the motor for an electric vehicle is controlled with the same responsiveness. be able to.
As is well known, in a conventional electric vehicle, when a driver depresses an accelerator pedal, the motor driving force control device controls the driving motor in accordance with the depression amount.
[0003]
[Non-Patent Document 1]
Matsushita Technical Journal 1998-April
[0004]
[Problems to be solved by the invention]
However, with regard to the above-mentioned accelerator operation such as depressing or returning the accelerator pedal, there is nothing more than turning the accelerator on and off once per second, and even in the case of frequent accelerator operations, the range is at most 1 to 2 Hz. It is.
Therefore, although there is a difference of about 100 times in response, the high response performance inherent in the motor is not controlled.
[0005]
By the way, when the vehicle is traveling at a constant speed, the wheel speed (wheel peripheral speed) Vw from when the wheel touches the ascending step on the road surface until it gets on the ascending step and leaves is as shown in the time chart of FIG. become.
At time t0 in the figure, the wheel starts to contact the convex step, and accordingly, the wheel speed Vw decreases from time t0 to t1.
Next, the wheel speed Vw increases from the time t1 to the time t2 than the wheel speed at the time t0, the wheel speed Vw keeps increasing from the time t2 to the time t3, and finally the wheel speed Vw decreases from the time t3 to the time t4. Return to wheel speed value equivalent to vehicle speed.
Thus, when the wheel passes the road surface step portion, the wheel speed Vw fluctuates despite the vehicle traveling at a constant speed.
Such fluctuations in the wheel speed Vw cause the vehicle body to vibrate back and forth as shown as vehicle body longitudinal vibration in FIG.
[0006]
In addition, as the wheel passes the ascending step, the tire collides with the road surface step, and the tire deformation process from the start of deformation of the tire itself until the end of restoration also causes longitudinal vibration in the vehicle body via the wheel. It will be a cause.
[0007]
FIG. 14 is a time chart showing the variation of the wheel speed Vw and the time-dependent change of the longitudinal vibration generated in the vehicle body when the wheel passes the road surface step.
These fluctuations of the wheel speed Vw and the longitudinal vibration of the vehicle body caused by the tire deformation process naturally deteriorate the riding comfort of the vehicle.
[0008]
The present invention pays attention to the high response performance of a drive motor of an electric vehicle, and prevents the vehicle body longitudinal vibration generated when a wheel passes a road step by high response drive force control via the motor. Propose technology.
[0009]
[Means for Solving the Problems]
For this purpose, a driving force control device for passing an electric vehicle according to the present invention includes a standard driving force calculating means, a road surface step detecting means, an additional driving force calculating means, and a combined driving force. The calculation means and the motor driving force control means are provided.
The standard driving force calculation means calculates a standard driving force according to the driving state of the vehicle,
The road surface step detecting means detects the road surface step through which the wheel passes during traveling,
The additional driving force calculating means calculates an additional driving force of the wheel that reduces the wheel speed fluctuation caused by the passage of the step according to the detected road surface step.
The combined driving force calculating means calculates a combined driving force by adding the additional driving force and the standard driving force,
The motor driving force control means controls the driving force of the motor so that the combined driving force is applied to the wheels.
[0010]
【The invention's effect】
According to the configuration of the present invention, when the wheel passes through the road surface step, the additional driving force that reduces the wheel speed fluctuation caused by the step passage and the standard driving force according to the vehicle driving state In order to give the combined driving force that is the sum value to the wheels,
It is possible to suppress the fluctuation of the wheel speed when passing through the step, to reduce the longitudinal vibration of the vehicle body caused by this, and to improve the riding comfort of the vehicle.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a power train of an electric vehicle (electric vehicle) having a step-passage driving force control device according to an embodiment of the present invention together with its control system, and 1 is a wheel driven by a motor 2. is there.
Although only one wheel 1 is shown in FIG. 1, the motor 2 drives a plurality of wheels with electric power from the battery 4 under the control of the motor driving force control means 3.
[0012]
The driving force command to the motor driving force control means 3 is determined by the driving force control device 5 as described in detail later.
Therefore, the driving force control device 5 includes a signal from an accelerator opening sensor 7 that detects a depression position of the accelerator pedal 6 (also referred to as an accelerator pedal depression amount or an accelerator opening) APO,
A signal from a wheel speed sensor 8 that detects a rotational peripheral speed Vw of the wheel 1 (also referred to herein as a wheel speed);
A signal from a distance sensor 9 which is disposed at a vehicle body location directly above the drive wheel 1 and detects a distance d from the vehicle body to the road surface;
A signal from the air pressure sensor 10 for detecting the tire air pressure of the wheel 1 is input.
[0013]
The driving force control device 5 includes a standard driving force calculation unit 20, a road surface step detection unit 30, an additional driving force calculation unit 40, and a combined driving force calculation unit 50.
Based on the accelerator opening APO, the standard driving force calculation means 20 calculates a standard driving force Td that is a driving force of the wheel that is required during normal traveling when the vehicle does not pass through the step.
When the accelerator opening APO is small, the standard driving force Td is also small, and when the accelerator opening APO is large, the standard driving force Td is also large.
[0014]
The road surface step detecting means 30 executes the control program of FIG. 2 based on the distance d from the vehicle body to the road surface detected by the distance sensor 9 to detect the road surface step through which the wheel 1 passes, or the wheel speed Based on the wheel speed Vw detected by the sensor 8, the control program of FIG. 3 is executed to detect a road surface step through which the wheel 1 passes.
First, the road surface step detection process shown in FIG. 2 will be described. This process is executed by a periodic interruption every minute fixed time Δt.
In step S21, the distance between the vehicle body and the road surface d (t) measured by the sensor 9 at a certain time t is read and temporarily stored in the history memory S22, and the past d ( Data regarding t) is also accumulated.
[0015]
In the next step S23, the vehicle body / road surface distance d (t−Δt) before the calculation cycle Δt is read from the history memory S22, and the change amount Δd (t) of the vehicle body / road surface distance in the calculation cycle Δt is next. Calculated by calculating the formula.
Δd (t) = d (t) −d (t−Δt) (1)
In the next step S24, the change rate Δd (t) / Δt of the vehicle body / road surface distance is calculated by dividing the change amount Δd (t) of the vehicle body / road surface distance by the calculation period Δt.
[0016]
In the next step S25, it is determined whether the time change rate Δd (t) / Δt of the distance between the vehicle body and the road surface is equal to or less than a certain negative value γ. Here, the constant amount γ is a threshold value that is set for determining a step regarding the rate of change in the distance from the road surface. If the rate of change in the distance to the road surface is greater than or equal to a negative constant γ, it indicates that the distance from the road surface is not rapidly shortening, that is, there is no road surface step. Reset the detection flag to 0.
On the other hand, if it is determined in step S25 that the rate of change in the distance from the road surface is smaller than the negative threshold γ, the distance from the road surface is rapidly shortened to indicate that the vehicle has crossed an ascending step during the time Δt. The process proceeds to step S26, where it is determined whether or not the amount of change in the distance between the vehicle body and the road surface, that is, the road surface step amount Δd (t) is equal to or less than a certain amount ε.
[0017]
This constant amount ε is a threshold value that is set for determining a step with respect to an amount of change in the distance to the road surface (a road surface step amount), and is a negative constant. When the amount of change in the distance to the road surface is greater than or equal to the negative constant ε, the step is advanced to step S29 to indicate that the ascending step is not so large as to require the driving force control according to the present invention, and the step detection flag is set. Reset to zero.
On the other hand, if it is determined in step S26 that the amount of change in the distance from the road surface is smaller than the negative threshold ε, the process proceeds to step S27 to indicate that the ascending step is large enough to require the driving force control according to the present invention. Here, the time t0 when the large road surface step is detected is stored, and the step amount Δd (t) at the time is stored as the detected step amount Δd (t0).
Thereafter, in step S28, the step detection flag is set to 1 to indicate that the large step is detected.
[0018]
The road surface step detecting means 30 in FIG. 1 can perform road surface step detection processing by the control program shown in FIG. 3 instead of FIG. 2, and in FIG. 3, the wheel speed Vw when passing the road surface step is as described above with reference to FIG. Therefore, the road surface level difference is detected by monitoring this.
In step S31, the wheel speed Vw (t) measured by the wheel speed sensor 8 at a certain time t is read and temporarily stored in the history memory S32. In the history memory, data on past Vw (t) is stored. Shall also be accumulated.
[0019]
In the next step S33, the wheel speed Vw (t−Δt) before the calculation cycle Δt is read from the history memory S32, and the change amount ΔVw (t) of the wheel speed during the calculation cycle Δt is calculated by the following calculation.
ΔVw (t) = Vw (t) −Vw (t−Δt) (1)
In the next step S34, the wheel speed change rate ΔVw (t) / Δt is calculated by dividing the wheel speed change amount ΔVw (t) by the calculation period Δt.
[0020]
In the next step S35, it is determined whether or not the wheel speed time change rate ΔVw (t) / Δt is less than a negative fixed amount α. Here, the constant amount α is a threshold value that is determined for determining a step regarding the wheel speed change rate. If the rate of change of the wheel speed is greater than or equal to the negative constant α, it is indicated that the wheel has not started contact with the step, as is apparent from the time chart of FIG. In step S39, the step detection flag is reset to zero.
On the other hand, if it is determined in step S35 that the time change rate ΔVw (t) / Δt of the wheel speed is smaller than the negative threshold value α, the wheel speed decreases rapidly, indicating that the wheel is about to pass through the step. Therefore, the process proceeds to step S36, where it is determined whether or not the change amount ΔVw (t) of the wheel speed is equal to or less than a certain amount β.
The wheel speed change amount ΔVw (t) corresponds to the step amount as is apparent from FIG.
[0021]
This constant amount β is a threshold value used when determining a step using the wheel speed change amount ΔVw (t) corresponding to the road surface step amount, and is a negative constant. If the wheel speed change amount ΔVw (t) is greater than or equal to the negative constant β, it indicates that the ascending step is not so large as to require the driving force control according to the present invention. Reset to zero.
On the other hand, if it is determined in step S36 that the wheel speed change amount ΔVw (t) is smaller than the negative threshold value β, the step is shown to be large enough to require the driving force control according to the present invention. The time t0 at which the large road surface step is detected is stored, and the wheel speed change amount ΔVw (t) at the time is stored as the detected step amount ΔVw (t0).
Thereafter, in step S38, the step detection flag is set to 1 to indicate that the large step has been detected.
[0022]
When the additional driving force calculating means 40 shown in FIG. 1 detects a road step as shown in FIG. 2, the additional driving force calculating means 40 shown in FIG. 4 is based on the step detection time t0, the step amount Δd (t0), and the step detection flag. The additional driving force Ta required to reduce the vibration transmitted from the wheel to the vehicle body when the wheel passes through the road surface step is calculated.
In step S41, it is checked whether or not the step detection flag is 1, that is, whether or not a step requiring driving force control according to the present invention is detected. If the level difference detection flag is 0, the level difference is not detected and the driving force control according to the present invention is not necessary. Therefore, in step S49, the additional driving force Ta is set to 0, and this is calculated as the combined driving force calculating means shown in FIG. 50.
On the other hand, when it is determined in step S41 that the level difference detection flag is 1, a level difference requiring driving force control according to the present invention has been detected, so control proceeds to step S42 and the road level level difference detection means 30 in FIG. The step detection time t0 and the step amount Δd (t0) obtained as shown in FIG. 2 are read, and based on these, the additional driving force Ta for reducing vibration generated when the step passes is calculated as follows.
[0023]
The vibration generated on the vehicle body side when the wheel 1 passes the road surface step is governed by the elastic characteristics and air pressure of the rubber of the tire itself, the spring characteristics of the suspension device, the vehicle speed, and the like. There is a method of sequentially calculating the required additional driving force from step information such as the height of the step.
However, since the calculation load applied to the arithmetic device is large in the sequential calculation method, it is desirable to employ a method with higher calculation efficiency when it is desired to calculate the additional driving force Ta in a very short time.
Therefore, in FIG. 4, the pattern of the additional driving force Ta required based on the governing factor is previously mapped as an additional driving force reference map, and this is read and used.
[0024]
Therefore, in step S43, as shown in FIG. 6, based on the elastic characteristics of the tire, tire pressure, suspension characteristics, vehicle speed, etc. (only the sensor 10 relating to tire pressure is shown in FIG. 1 and other sensors relating to information are omitted). The reference waveform map of the additional driving force reference value Tq on the time (τ) axis is read, and the time t0 and the map origin τ = 0 are made coincident.
The reference waveform map of the additional driving force reference value Tq is from the contact start time τ = 0 at which the wheel starts to contact the road surface step to the end time τ = τe at which the vibration on the vehicle body ends damping. The time-series change of the additional driving force Ta required to reduce the vibration of is mapped.
[0025]
Incidentally, the additional driving force Ta needs to be increased or decreased according to the magnitude of the road surface step amount Δd (t0). Therefore, in step S44, the step amount based on the map of the amplitude gain G illustrated in FIG. 7 prepared in advance. The amplitude gain G is retrieved from Δd (t0).
In step S45, the additional driving force Ta is calculated from the additional driving force reference value Tq and the amplitude gain G based on the following equation.
Ta (t0 + τ) = G {Δd (t0)} × Tq (τ)
In step S46, the additional reference force Ta (t0 + τ) calculated above is transmitted to the combined driving force calculation means 50 in FIG.
[0026]
In step S47, it is checked whether or not τ ≧ τe on the time (τ) axis in FIG. 6 and whether or not the output of the additional driving force Ta should be terminated is checked.
Until τ ≧ τe, the control is returned to step S43, and the additional driving force Ta is continuously calculated by repeating the above loop.
Therefore, the additional driving force Ta becomes a waveform obtained by amplifying the waveform of the additional driving force reference value Tq as shown in FIG. 6 with the amplitude gain G corresponding to the step amount Δd (t0). The larger the amount Δd (t0), the larger the waveform.
If it is determined in step S47 that τ ≧ τe, the output of the additional driving force Ta should be terminated, so the step detection flag is reset to 0 in step S48.
[0027]
When the additional driving force calculating means 40 of FIG. 1 detects a road surface step as shown in FIG. 3, the additional driving force calculating means 40 is based on the step detection time t0, the step amount ΔVw (t0), and the step detection flag as a result of the detection. The control program shown in FIG. 5 is executed instead of 4, and the additional driving force Ta required to reduce the vibration transmitted from the wheel to the vehicle body side when the wheel passes the road surface step is calculated.
[0028]
FIG. 5 replaces step S42, step S44, and step S45 in FIG. 4 with step S52, step S54, and step S55, respectively, and all other steps are the same as the steps indicated by the same reference numerals in FIG. Shall be performed.
In step S52, which is selected when it is determined in step S41 that the level difference detection flag is 1 (a level difference requiring driving force control according to the present invention is detected), the road surface level difference detection unit 30 in FIG. The step detection time t0 and the step amount ΔVw obtained as shown in FIG. 3 are read.
[0029]
In the next step S43, the reference waveform map of the additional driving force reference value Tq on the time (τ) axis as shown in FIG. 6 is read in the same manner as described above with reference to FIG. = 0.
In the next step S54, the amplitude gain G is searched and obtained from the step amount ΔVw (t0) based on a map of amplitude gain G illustrated in FIG. 7 prepared in advance.
In step S55, the additional driving force Ta is calculated from the additional driving force reference value Tq and the amplitude gain G based on the following equation.
Ta (t0 + τ) = G {ΔVw (t0)} × Tq (τ)
[0030]
FIG. 8 is a modified example of the additional driving force calculation program shown in FIG. 5. Step S 61 is added between step S 43 and step S 54 in FIG. 5, step S 55 is replaced with step S 65, and step S 54 and step S 65 are added. Step S62 is added.
Only steps different from those in FIG. 5 will be described below.
[0031]
In step S61 selected after the process of step S43, a time gain K for correcting the time axis τ of the additional driving force reference value (Tq) map shown in FIG. 6 is read.
The time gain K is determined in advance according to the wheel speed Vw (t0−Δt) immediately before the step detection as illustrated in FIG. 9, and the wheel speed Vw (t0−) immediately before the step detection is based on the map of FIG. The time gain K is obtained from the search from [Delta] t).
[0032]
In step S62, which is selected after the amplitude gain G is read as described above in step S54, the gain correction coefficients H and H ′ for correcting the gains G and K according to the tire air pressure of the wheel 1 are read.
In reading these gain correction coefficients H and H ′, gain correction is performed from tire pressure detected by the sensor 10 (see FIG. 1) based on a map of gain correction coefficients H and H ′ illustrated in FIG. 10 prepared in advance. The coefficients H and H ′ are obtained.
[0033]
In the next step S65, the following formula is obtained from the additional driving force reference value Tq obtained in step S43, the gains G and K determined in step S54 and step S61, and the gain correction coefficients H and H ′ obtained in step S62. Based on this, the additional driving force Ta is calculated, and the process proceeds to the next step S46.
Ta (t0 + τ) = G {ΔVw (t0)} × H × Tq (K × H ′ × τ)
Thus, when calculating the additional driving force Ta from the additional driving force reference map Tq, the additional driving considering the air pressure of the tire attached to the wheel 1 and the wheel speed (vehicle speed) when approaching the road surface step. The force Ta can be calculated.
[0034]
As shown in the block diagram of FIG. 11, the combined driving force calculating means 50 shown in FIG. 1 includes a filter processing unit 51 and a combined driving force calculating unit 52, and includes the standard driving force Td (t) and the additional driving force Ta. From (t), a combined driving force Tt (t) which is the sum of these is calculated, and this is instructed to the motor driving force control means 3 (see also FIG. 1), so that the combined driving force Tt (t ) Is controlled to drive the motor 2.
[0035]
The filter processing unit 51 in FIG. 11 is a low-pass filter, which is filtered through a standard driving force Td (t) to remove high-frequency noise components harmful to motor driving force control, and the standard driving force Tdf (t ) Is output.
The combined driving force calculation unit 52 receives the standard driving force Tdf (t) and the additional driving force Ta (t) after the filter processing, and calculates the combined driving force Tt by adding them as in the following equation. This is commanded to the motor driving force control means 3.
Tt (t) = Tdf (t) + Ta (t)
If the additional driving force Ta (t) is input to the combined driving force calculation unit 52 without filtering, the waveform of the additional driving force Ta (t) including a high-frequency component is attenuated and an effective effect cannot be obtained. This is to avoid this.
[0036]
If the filter processing unit 53 is also provided in the motor driving force control means 3 as shown in FIG. 12, depending on the model, the combined driving force calculation means 50 is shown in FIG. It is assumed that the driving force calculation unit 52 is not provided, and this means 50 inputs the filtered standard driving force Tdf (t) and the additional driving force Ta (t) as they are to the motor driving force control means 3 without adding them up. To do.
[0037]
In addition to the input filter processing unit 53, the motor driving force control means 3 has a combined driving force calculation unit 54 and a current control unit 55. The input filter processing unit 53 uses the filtered standard driving force Tdf (t). The standard driving force Tdff (t) after the predetermined filter processing is input to the combined driving force calculation unit 54.
Separately, the additional driving force Ta (t) is directly input to the combined driving force calculation unit 54, and the combined driving force calculation unit 54 receives the standard driving force Tdff (t) after being processed by the input filter processing unit 53 and the additional driving force The combined driving force Tt (t) is calculated by the following equation that adds the driving force Ta (t), and this is instructed to the current control unit 55.
Tt (t) = Tdf (t) + Ta (t)
[0038]
The current control unit 55 is connected to the battery 4 such as a constant voltage source and the motor 2 (both see FIG. 1) via a power cable, and receives the command of the combined driving force Tt (t), and the wheel 1 is combined. A current necessary for outputting the driving force Tt is supplied to the motor 2.
[0039]
FIG. 13 is an operation time chart of the above-described step-pass driving force control, and shows an operation under the same conditions as in FIG.
13A and 13C, the waveform of the wheel speed Vw and the waveform of the vehicle longitudinal vibration in FIG.
[0040]
According to the step-passing driving force control, when the wheel 1 comes into contact with the step at time t0 in FIG. 13, the road surface step detecting means 30 detects this from time t0 to t1, and the additional driving force calculating means 40 is detected. Calculates the additional driving force Ta as shown in FIG.
The combined driving force calculation means 50 adds this additional driving force Ta to the standard driving force Td and provides it for driving force control of the motor 2.
With this additional driving force Ta, the wheel speed Vw is improved from the waveform shown by the broken line to the waveform shown by the solid line, and the change in the wheel speed is reduced, and the longitudinal vibration of the vehicle body is also improved from the waveform shown by the broken line to the waveform shown by the solid line. Thus, the ride comfort of the vehicle can be improved.
[0041]
Further, in the above-mentioned driving force control at the time of step passing, the road surface step detecting means 30 is detected by the wheel speed sensor 8 instead of detecting the road surface step based on the distance d from the vehicle body to the road surface detected by the distance sensor 9. By detecting the road surface step on the basis of the wheel speed fluctuation, it is possible to realize a step-pass driving force control excellent in responsiveness while directly monitoring the wheel speed fluctuation. Furthermore, the distance sensor can be omitted, and the number of parts can be reduced.
[0042]
Further, the additional driving force calculating means 40 reads the amplitude gain G with respect to the wheel speed Vw (t0) at the time of detecting the step and corrects the additional driving force Ta, so that the additional driving force according to the vehicle speed can be accurately calculated. This can effectively reduce vehicle body vibration.
[0043]
In the present embodiment, the vehicle body vibration can be effectively reduced by correcting the amplitude gain G and the time gain K using the gain correction coefficients H and H ′ for the tire air pressure of the wheel 1.
[0044]
Further, the combined driving force calculation means 50 filters the standard driving force Td and calculates the combined driving force by adding the standard driving force Tdf after the removal of the high frequency noise component and the additional driving force Ta, thereby achieving high accuracy. It is possible to control the driving force when passing through a step.
[0045]
Further, the additional driving force calculating means 40 determines the additional driving force Ta using the amplitude gain G based on the road surface step amount Δd (t0) in the process of step S44 in FIG. The vehicle body vibration can be effectively reduced.
[0046]
In the present embodiment, the control for the up step is shown as an example. However, the control for the down step is performed by the same configuration, and the control for the up step and the control for the down step are combined, so that an upper limit up to about 100 Hz is obtained. Thus, the vibration of the vehicle body can be eliminated even when overcoming a convex step, a concave step or a continuous step, which can greatly contribute to the reduction of the vehicle body vibration.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram showing a power train of an electric vehicle provided with a step-passage driving force control apparatus according to an embodiment of the present invention, together with its control system.
FIG. 2 is a flowchart showing a step detection control program executed by a road surface information detection means by a scheduled interruption based on a distance sensor measuring a distance from a vehicle body to a road surface.
FIG. 3 is a flowchart showing a step detection control program that is measured by a wheel speed sensor and a road surface information detection means executes by a scheduled interruption based on the measured wheel rotation speed.
FIG. 4 is a flowchart showing a control program executed by an additional driving force calculating means to calculate an additional driving force Ta.
FIG. 5 is a flowchart showing another control program executed by the additional driving force calculating means to calculate the additional driving force Ta.
FIG. 6 is a characteristic diagram of a reference additional driving force Tq.
FIG. 7 is a characteristic diagram of amplitude gain G;
FIG. 8 is a flowchart showing still another control executed by the additional driving force calculating means to calculate the additional driving force Ta.
FIG. 9 is a characteristic diagram of time gain K;
FIG. 10 is a characteristic diagram of gain correction coefficients H and H ′.
FIG. 11 is a functional block diagram showing a combined driving force calculation unit;
FIG. 12 is a functional block diagram showing a motor controller when a filter processing unit is provided inside the motor driving force control means;
FIG. 13 is an operation time chart of driving force control at the time of step passing according to the present embodiment.
14 is similar to FIG. 13 with respect to fluctuations in the rotational speed of the wheels and changes with time of vibrations generated in the vehicle body when a vehicle that does not have a step force driving force control device according to the present invention passes the steps. It is a time chart which shows the operation | movement on conditions.
[Explanation of symbols]
1 wheel
2 Wheel motor
3 Motor driving force control means
4 battery
5 Driving force control device
6 Accelerator pedal
7 Accelerator position meter
8 Wheel speed sensor
9 Distance sensor
10 Tire pressure sensor
20 Standard driving force calculation means
30 Road surface level detection means
40 Additional driving force calculation means
50 Composite driving force calculation means

Claims (7)

In an electric vehicle that drives wheels by a motor,
Standard driving force calculating means for calculating a standard driving force according to the driving state of the vehicle;
Road surface step detecting means for detecting a road surface step through which the wheel passes during traveling;
An additional driving force calculating means for calculating an additional driving force of the wheel so as to reduce a wheel speed fluctuation caused by the passage of the step according to the road surface step detected by the means;
A combined driving force calculating means for calculating a combined driving force by adding the additional driving force and the standard driving force;
A driving force control device at the time of step passage of an electric vehicle, comprising: motor driving force control means for controlling the driving force of the motor so that the combined driving force is applied to the wheels. In the driving force control device at the time of passing the step of the electric vehicle according to claim 1,
The road surface level difference detecting means detects a road level level difference based on a change in wheel speed, and a driving force control device at the time of level difference passing of an electric vehicle. In the drive force control apparatus at the time of level | step difference passage of the electric vehicle of Claim 1 or 2,
The additional driving force calculating means is configured to correct the additional driving force in accordance with the wheel speed at the time of detecting the step, and the driving force control device at the time of passing the step of the electric vehicle. In the driving force control apparatus at the time of level | step difference passage of the electric vehicle of any one of Claim 1 thru | or 3,
The additional driving force calculation means is configured to correct the additional driving force according to the tire air pressure of the wheel, and the driving force control device at the time of step passage of the electric vehicle. The driving force control device at the time of step passage of an electric vehicle according to any one of claims 1 to 4, wherein the combined driving force calculation means filters the standard driving force.
The combined driving force calculating means is configured to calculate a combined driving force by adding an additional driving force to a standard driving force after the filtering process, and a driving force control device at the time of a step passage of an electric vehicle. 6. The driving force control device at the time of step passage of an electric vehicle according to any one of claims 1 to 5, wherein the motor driving force control means filters an input motor driving force control command. In
The motor driving force control means receives the standard driving force as the motor driving force control command, and adds the additional driving force to the filtered standard driving force after the filtering process is completed for the standard driving force. A driving force control device at the time of passing a step of an electric vehicle, characterized in that the combined driving force obtained in this way is contributed to driving force control of the motor. In the driving force control apparatus at the time of level difference passage of an electric vehicle given in any 1 paragraph of Claims 1 thru / or 5,
The additional driving force calculating means is configured to determine the additional driving force based on a road surface step amount.

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