WO2015002033A1

WO2015002033A1 - Drive torque control device

Info

Publication number: WO2015002033A1
Application number: PCT/JP2014/066728
Authority: WO
Inventors: 崇志瀬尾
Original assignee: 日産自動車株式会社
Priority date: 2013-07-04
Filing date: 2014-06-24
Publication date: 2015-01-08

Abstract

Provided is a drive torque control device capable of suppressing a drive torque error in the actual drive torque relative to the torque command value in a drive unit even during a period other than when travelling in a straight line. The drive torque control device is characterized in that a vehicle controller (11) is provided with a portion that executes a process illustrated in a flowchart shown in Fig. 3B for correcting a torque command value (tTm) to be outputted to the electric motor (3) of at least one of the left and right drive units (WD, WD) on the basis of lubricant temperature (To), motor temperature (Tmo), and pump lubricant amount (Ov), which are drive-torque shift factors causing the actual drive torque to shift from the target drive torque for the right and left drive units (WD, WD), said correction being carried out so that the torque difference between the actual drive torque of the left drive unit (WD) and the actual drive torque of the right drive unit (WD) approaches the torque difference between the right and left drive units (WD, WD) when no torque difference exists between the target drive torque and the actual drive torque in the right and left drive units (WD, WD).

Description

Drive torque control device

The present invention relates to a drive torque control device that controls the drive torque of left and right drive wheels independently in a vehicle.

2. Description of the Related Art Conventionally, a drive torque control device that controls left and right drive torques independently is known (see, for example, Patent Document 1).
In such left and right independent drive torque control, an error may occur in the actual drive torque with respect to the torque command value depending on the state of the left and right drive units and changes in the environment. In order to prevent such a problem that the drive torque error differs between right and left, in the prior art, the actual drive torque of the left and right wheels is detected by a torque sensor, and the target drive torque (torque command value) is based on the deviation between the two. I am trying to correct.

JP 2005-160262 A

However, in the above prior art, since the actual driving torque of the left and right wheels is detected and correction is performed based on the deviation, for example, only in a traveling state where the driving torques of the left and right wheels coincide with each other, such as straight traveling, Correction cannot be performed. In other words, it is difficult to perform correction even if there is an error in the actual drive torque with respect to the torque command value during control in which the target drive torque of the left and right drive wheels is different, such as during vehicle attitude control or turning. there were.
In addition, there is a problem of increased cost due to the installation of the torque sensor.

The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a drive torque control device capable of suppressing the drive torque error amount of the actual drive torque with respect to the torque command value in the drive unit even when traveling straight ahead. And

In order to achieve the above object, the present invention provides:
Torque control means for independently controlling at least one of left and right drive torques of the motors of the left drive unit and the right drive unit;
Based on the detected value of the left driving torque change factor detected by the first detecting means and the detected value of the right driving torque change factor detected by the second detecting means, the actual driving torque of the left driving unit and the right side At least one of the two drive units is such that the left-right torque difference from the actual drive torque of the drive unit approaches the left-right torque difference when there is no error between the torque command value and the actual drive torque in the left and right drive units. The driving torque control device includes a correcting unit that corrects the torque command value output to the motor.

In the drive torque control device of the present invention, the correction means detects the drive torque error amount of the actual drive torque with respect to the torque command value based on the detected value of the left and right drive torque change factors without detecting the actual drive torque. The torque command value is corrected so as to decrease.
Therefore, even when different torque command values are intentionally given to the left and right drive wheels, such as during vehicle attitude control other than straight running, based on the detected values of the left and right drive torque change factors, It can correct | amend so that the drive torque error amount of the actual drive torque with respect to a torque command value may be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic system diagram which shows the whole control system regarding the drive system of the electric vehicle provided with the drive torque control apparatus of Embodiment 1 of this invention. FIG. 3 is a cross-sectional view showing a drive unit applied to the drive torque control device of the first embodiment. FIG. 6 is a flowchart showing a flow of torque correction processing in the drive torque control apparatus of Embodiment 1, and shows a flow of processing for calculating a driving force error in the left and right drive units. FIG. FIG. 6 is a flowchart showing a flow of torque correction processing in the drive torque control apparatus of Embodiment 1, and shows a flow of correction processing based on the calculated error amount. FIG. Left rear wheel for explaining the relationship between torque command value, driving force error, and correction amount in the left and right driving units corresponding to the lubricating oil temperature as the driving force change factor used in the driving force control apparatus of the first embodiment They are an oil temperature-drive torque error map, a left rear wheel command current map, a right rear wheel oil temperature-drive torque error map, and a right rear wheel command current map. Left rear wheel motor temperature for explaining the relationship between the torque command value, the actual drive torque, and the correction amount in the left and right drive units based on the motor temperature as the drive torque change factor used in the drive torque control apparatus of the first embodiment -A drive torque error map, a left rear wheel command current map, a right rear wheel motor temperature-a drive torque error map. Left rear wheel for explaining the relationship between the torque command value, the actual drive torque, and the correction amount in the left and right drive units based on the amount of pump lubricating oil as a drive torque change factor used in the drive torque control device of the first embodiment They are a pump lubricant amount-drive torque error map, a left rear wheel command current map, a right rear wheel pump lubricant amount-drive torque error map, and a right rear wheel command current map. Left rear wheel oil temperature-drive torque error map for explaining the relationship between the torque command value, the actual drive torque, and the correction amount in the left and right drive units corresponding to the lubricating oil temperature in the drive torque control apparatus of the second embodiment , Left rear wheel command current map, right rear wheel oil temperature-drive torque error map, and right rear wheel command current map. 5 is a time chart illustrating an operation example for explaining a relationship between a basic target driving torque and a left and right target driving torque at the time of vehicle attitude control (yaw moment control) in the embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the drive torque control apparatus of this invention is demonstrated based on embodiment shown in drawing.
(Embodiment 1)
First, the overall configuration of an electric vehicle provided with the drive torque control device of the first embodiment will be described.
FIG. 1 is a schematic system diagram showing an overall control system related to a braking / driving system of an electric vehicle provided with a driving torque control apparatus according to Embodiment 1 of the present invention.

This electric vehicle includes left and right front wheels 1FL and 1FR and left and right rear wheels 1RL and 1RR. The left and right rear wheels 1FL, 1FR are used as driving wheels and can be driven by individual electric motors 3RL, 3RR (in-wheel motor IWM) built in the respective driving units WD, and the left and right front wheels 1FL, Steering is possible by turning 1 FR.

The electric motors 3RL and 3RR are motor / generators that can also function as a generator, and can regeneratively brake the left and right rear wheels 1RL and 1RR that are motor-driven as described above in response to a predetermined power generation load.

Further, the electric vehicle shown in FIG. 1 includes a vehicle controller 11 that performs drive control and regenerative control of the electric motors 3RL and 3RR (in-wheel motor IWM). The vehicle controller 11 can execute vehicle behavior control by causing differential rotation of the left and right rear wheels 1RL and 1RR based on drive control of the electric motors 3RL and 3RR (in-wheel motor IWM).

The vehicle controller 11 includes an accelerator opening sensor 12, a steering angle sensor 13, a yaw rate sensor 14, a longitudinal acceleration sensor 15, a lateral acceleration sensor 16, wheel speed sensors 17RL and 17RR, an oil temperature sensor 18, a motor temperature sensor 19, and a pump P. A signal is input from.

The accelerator opening sensor 12 detects an accelerator opening APO that is an accelerator pedal depression amount (not shown).
The steering angle sensor 13 detects the steering angle θ of the steering wheel.
The yaw rate sensor 14 detects a yaw rate φ that is a behavior around the vertical axis of the vehicle.
The longitudinal acceleration sensor 15 detects the longitudinal acceleration Gx of the vehicle.
The lateral acceleration sensor 16 detects the lateral acceleration Gy of the vehicle.
The wheel speed sensors 17RL and 17RR detect the wheel speeds VwL and VwR of the left and right rear wheels 1RL and 1RR driven by the motor.
The oil temperature sensor 18 detects the lubricating oil temperature To as a left and right driving torque change factor in each drive unit WD as the first detection means and the second detection means.
The motor temperature sensor 19 uses a motor temperature Tmo, which is a temperature as a left / right driving torque change factor of a stator 31 (to be described later) of each of the electric motors 3RL and 3RR (in-wheel motor IWM) as first detection means and second detection means. To detect.
In addition, a signal indicating a pump lubricating oil amount Ov (oil amount L / min per unit time) as a left-right driving torque change factor is input to the vehicle controller 11 from a pump P that discharges lubricating oil, which will be described later. .

Based on the input information from these sensors 12 to 16, 17RL, 17RR, 18, 19 and pump P, the vehicle controller 11 drives the target motor torques tTmL, tTmR of the electric motors 3RL, 3RR that drive the left and right rear wheels 1RL, 1RR. Ask for.
Further, the vehicle controller 11 outputs these target motor torques tTML and tTmR as torque command values tTm to the inverter 20 that performs drive / regeneration control of the electric motors 3RL and 3RR, respectively. The torque command value tTm is a command value of actual drive torque from the drive unit WD. Therefore, the target motor torques tTmL and tTmR based on the torque command value tTm are also motor torques for obtaining the actual driving torque.

The inverter 20 supplies DC-AC converted power from the battery (not shown) to the electric motors 3RL and 3RR according to the target motor torques tTML and tTmR. As a result, the left and right rear wheels 1RL, 1RR are driven or regenerated by the motor torques TmL, TmR formed in the electric motors 3RL, 3RR.

(Configuration of drive unit)
Next, the configuration of the drive unit WD provided with the electric motors 3RL, 3RR (in-wheel motor IWM) will be described with reference to FIG. In the following description, the electric motors 3RL and 3RR are simply referred to as the electric motor 3 unless a difference between left and right is specified.

FIG. 2 is a longitudinal sectional view of the drive unit WD, and the in-wheel motor unit is accommodated in the unit case 100. The unit case 100 is configured by coupling a case main body 101 and a rear cover 102.

The unit case 100 houses the electric motor 3 and the planetary gear set 40.
The electric motor 3 includes an annular stator 31 fitted and fixed to the inner periphery of the case body 101, and a rotor 32 disposed concentrically with a radial gap on the inner periphery of the stator 31. .

The planetary gear set 40 functions as a speed reduction mechanism that couples the input shaft 51 and the output shaft 52 that are arranged to face each other in a coaxial manner, and that decelerates the rotation of the input shaft 51 and transmits it to the output shaft 52.
The planetary gear set 40 includes a sun gear 41, a ring gear 42, and a planetary pinion 43.
The sun gear 41 is provided integrally with the input shaft 51.
The ring gear 42 is coaxial with the sun gear 41 and is supported by the case body 101 at a position shifted in the axial direction from the sun gear 41.

The planetary pinion 43 has a stepped structure provided so as to mesh with the sun gear 41 and the ring gear 42, and is supported by the pinion shaft 44. Further, the pinion shaft 44 is supported by a carrier 45, and the carrier 45 rotates integrally with the output shaft 52.

Further, a wheel hub 53 is coupled to the output shaft 52, and a brake drum 54 is coupled to the wheel hub 53 concentrically. The wheel 60 of the wheel W is coupled to the wheel hub 53 by bolts 61.

The unit case 100 stores lubricating oil OIL, and the pump P forcibly supplies the lubricating oil OIL to the planetary gear set 40 and the electric motor 3 to perform lubrication and cooling. .

<Operation of drive unit>
The operation of the drive unit WD described above will be described below.
When the stator 31 of the electric motor 3 is energized, the rotor 32 is rotationally driven by the electromagnetic force from now on, and the rotational driving torque is transmitted to the sun gear 41 of the planetary gear set 40 via the input shaft 51.

As a result, the sun gear 41 rotates the planetary pinion 43. Since the ring gear 42 fixed at this time functions as a reaction force receiver, the stepped planetary pinion 43 performs a planetary motion that rolls along the ring gear 42. Do.
The planetary movement of the planetary pinion 43 is transmitted to the output shaft 52 through the carrier 45, and the output shaft 52 is decelerated and rotated in the same direction as the input shaft 51.
Then, the rotation of the output shaft 52 is transmitted to the wheel W through the wheel hub 53 coupled thereto, and the wheel W is driven to rotate.

(Control by vehicle controller)
As described above, the vehicle controller 11 controls the drive of the drive units WD of the left and right rear wheels 1RL and 1RR.
In this drive control, in Embodiment 1, the torque command values tTm for the drive units WD and WD of the left and right rear wheels 1RL and 1RR are controlled independently.
In this case, control is normally performed so that the drive torques of the left and right rear wheels 1RL and 1RR are equal.

Further, the vehicle controller 11 also executes control for intentionally changing the driving torques of the left and right rear wheels 1RL and 1RR during well-known vehicle attitude control (yaw moment control) or the like.
As such vehicle attitude control, for example, a difference is given to the driving torque of the left and right rear wheels 1RL and 1RR so that the yaw rate of the vehicle matches the target yaw rate, and the yaw rate generated in the vehicle is increased or decreased. Control. In addition, when drive wheel slip occurs in the left and right rear wheels 1RL and 1RR, control for giving a drive torque difference to the left and right rear wheels 1RL and 1RR as described above is included.
The left and right drive torque control including the vehicle attitude control (yaw moment control) described above will be described.
That is, normally (such as when traveling straight), half of the vehicle target drive torque is set as the basic target drive torque Tmo (see FIG. 8) of the left and right drive units WD. At the time of vehicle attitude control, the attitude control torque ΔT is added to one of the left and right basic target drive torques Tmo to obtain the target drive torque of the drive unit WD of this one (right rear wheel 1RR in the example of FIG. 8). decide.
Further, the target drive torque of the other drive unit WD (left rear wheel 1RL in the example of FIG. 8) is determined by subtracting the attitude control torque ΔT from the basic target drive torque Tmo.
When the vehicle attitude control is not executed in the straight traveling state, the target drive torques of the left and right drive units WD are the basic target drive torques Tmo, which are equal to the left and right.
The vehicle target driving torque described above is a braking / driving torque according to the driving state requested by the driver based on information on the accelerator opening, the vehicle speed, and the braking force, as is well known. Half of this is the basic target drive torque Tmo.

(Drive torque correction control)
Next, drive torque correction control in the drive torque control apparatus of Embodiment 1 will be described based on the flowcharts of FIGS. 3A and 3B. This drive torque correction control is performed so that the actual drive torque of the electric motor 3 (drive unit WD) matches the torque command value tTm (that is, the torque command value = the actual drive torque of the drive unit WD). In this control, the drive torque error amount between them is corrected so as to decrease. Specifically, in the present embodiment, the drive torque of the electric motor 3 is increased by the planetary gear set 40 as a speed reduction mechanism and output from the drive unit WD, so the motor output is different from the actual drive torque.
In the flowchart of FIG. 3A, steps S1L to S4L and steps S1R to S4R are performed for the drive units WD of the left and right rear wheels 1RL and 1RR, which are drive wheels, respectively. Since the contents of the process are the same on the left and right, steps S1L to S4L, which are processes on the left rear wheel 1RL side, will be described as a representative of both.

First, in step S1L, a process for calculating the drive torque error amount ΔLTt is performed on the drive unit WD of the left rear wheel 1RL based on the lubricating oil temperature To detected by the oil temperature sensor 18.
The calculation of the drive torque error amount ΔLTt based on the lubricating oil temperature To is performed by calculating the left rear wheel oil temperature-drive torque degree difference map and the right rear wheel oil temperature-drive torque error map of the left and right drive units WD shown in FIG. Based on. The oil temperature-driving torque error map for each of the left and right rear wheels is determined based on the driving torque error amount of the actual driving torque (driving torque error amount ΔLTt) with respect to the torque command value tTm corresponding to the lubricating oil temperature To in the driving unit WD by experiment and simulation in advance. ) Is stored. In the oil temperature-driving torque error map for the left and right rear wheels shown in FIG. 4, the driving torque error amount ΔLTt is generated on the minus side as the lubricating oil temperature To is lower, while the driving torque error amount ΔLTt is on the plus side as the temperature is higher. It is set to the characteristic that occurs.

In step S2L, a process for calculating a drive torque error amount ΔLTm is performed for the left wheel based on the motor temperature Tmo detected by the motor temperature sensor 19.
This calculation is performed based on the left rear wheel motor temperature-drive torque error map and the right rear wheel motor temperature-drive torque error map of the left and right drive units WD shown in FIG. This motor temperature-driving torque error map stores the driving torque error amount (driving torque error amount ΔLTm) of the actual driving torque with respect to the torque command value tTm corresponding to the motor temperature Tmo in advance through experiments and simulations. In the left and right rear wheel motor temperature-driving torque error map shown in FIG. 5, the driving torque error amount ΔLTm is generated on the positive side as the motor temperature Tmo is lower, while the driving torque error amount ΔLTm is increased as the motor temperature Tmo is higher. Is set to a characteristic that occurs on the negative side.

In step S3L, a process of calculating a drive torque error amount ΔLTp based on the pump lubricant oil amount Ov of the drive unit WD is performed.
This calculation is performed based on the left rear wheel pump lubricant amount-drive torque error map and right rear wheel lubricant amount-drive torque error map of the left and right drive units WD shown in FIG. In this lubricating oil amount-driving torque error map, the driving torque error amount (driving torque error amount ΔLTp) with the actual driving torque with respect to the torque command value tTm corresponding to the pump lubricating oil amount Ov is stored in advance through experiments and simulations. Is. In the left and right rear wheel lubricating oil amount-driving torque error map shown in FIG. 6, the smaller the pump lubricating oil amount Ov, the more positive the driving torque error amount ΔLTp, while the larger the pump lubricating oil amount Ov, the more the driving. The torque error amount ΔLTp is set to a characteristic that occurs on the negative side.

In step S4L, a left rear wheel total drive torque error amount ΔLTtotal is calculated. The left rear wheel total drive torque error amount ΔLTtotal is a value obtained by adding the drive torque error amounts ΔLTt, ΔLTm, and ΔLTp calculated in steps S1L to S3L as shown in the following equation (1).
ΔLTtotal = ΔLTt + ΔLTm + ΔLTp (1)
When the left rear wheel total driving torque error amount ΔLTtotal is calculated by the processing of steps S1L to S4L and the right rear wheel total driving torque error amount ΔRTtotal is calculated by steps S1R to S4R, the process proceeds to step S5 shown in FIG. 3B. .

In step S5, whether or not the torque command value tTm needs to be corrected is determined for each of the left and right rear wheels 1RL and 1RR. This necessity determination is made by comparing each total drive torque error amount ΔLTtotal, ΔRTtotal with the necessity determination threshold value, and if both total drive torque error amounts ΔLTtotal, ΔRTtotal are below the necessity determination threshold value, the drive torque correction is unnecessary. Judge. This necessity determination threshold value is set in order to eliminate unnecessary correction of a small amount of drive torque error, and the value is set as appropriate.

If it is determined in step S5 that driving torque correction is unnecessary, the process proceeds to step S10, and if it is determined that at least one of the total driving torque error amounts ΔLTtotal and ΔRTtotal needs to be corrected, the process proceeds to step S6.
Then, in step S10, which proceeds when it is determined in step S5 that drive torque correction is unnecessary, the left rear wheel drive torque correction amount ΔLT and the right rear wheel drive torque correction amount ΔRT are set to zero.

On the other hand, in step S6 and step S7 that proceed when it is determined in step S5 that drive torque correction is necessary, it is determined whether or not the total drive torque error amounts ΔLTtotal and ΔRTtotal are within the control limit value range. To do. That is, as the control limit value, a control limit torque upper limit value Tmax that is the upper limit value and a control limit torque lower limit value Tmin that is the lower limit value are set.

In step S6, it is determined whether or not the total drive torque error amounts ΔLTtotal and ΔRTtotal are less than the control limit torque upper limit value Tmax. Then, when the total drive torque error amounts ΔLTtotal and ΔRTtotal are less than the control limit torque upper limit value Tmax, the process proceeds to step S7, and when the total drive torque error amounts ΔLTtotal, ΔRTtotal are equal to or greater than the control limit torque upper limit value Tmax, the process proceeds to step S11. As the control limit torque upper limit value Tmax, a preset motor rated torque of the electric motor 3 can be used. Alternatively, the maximum output power that can be output from the electric motor 3 can be calculated and used at this time by adding the battery charge amount, motor temperature, inverter temperature, and the like to the motor rated torque.

On the other hand, in step S7, it is determined whether each total drive torque error amount ΔLTtotal, ΔRTtotal is larger than the control limit torque lower limit value Tmin. If it is larger than the control limit torque lower limit value Tmin, the process proceeds to step S8, and if it is less than the control limit torque lower limit value Tmin, the process proceeds to step S12. The control limit torque lower limit value Tmin is the minimum controllable output value of the electric motor 3.

If the total drive torque error amounts ΔLTtotal, ΔRTtotal are within the control limit value range, that is, within the range between the control limit torque lower limit value Tmin and the control limit torque upper limit value Tmax, the process proceeds to step S8. In step S8, the left rear wheel drive torque correction amount ΔLT is set to the left rear wheel total drive torque error amount ΔLTtotal, and the right rear wheel drive torque correction amount ΔRT is set to the right rear wheel total drive torque error amount ΔRTtotal.

Further, in step S9 following step S8, values obtained by adding initial variation correction amounts α and β to the left rear wheel drive torque correction amount ΔLT and right rear wheel drive torque correction amount ΔRT set in step S8, respectively. The drive torque correction amounts are ΔLT and ΔRT. Then, the torque command current map is corrected according to the drive torque correction amounts ΔLT and ΔRT finally obtained in this way.
That is, each drive unit WD has initial variations due to component variations and assembly variations at the time of manufacture. Therefore, the error (variation) of the actual drive torque with respect to the torque command value tTm at the completion of the drive unit WD is measured and set (stored) in advance as initial variation correction amounts α and β. In step S9, the initial variation correction amounts α and β are added to the left rear wheel drive torque correction amount ΔLT and the right rear wheel drive torque correction amount ΔRT.

Next, correction of the torque command current map based on these drive torque correction amounts ΔLT and ΔRT will be described.
4, 5, and 6, the lower side is a torque command current map showing the relationship of the current value A to the torque command value tTm.
Here, correction of the torque command current map based on the respective drive torque correction amounts ΔLT and ΔRT when the lubricating oil temperature To shown in FIG. 4 is used as a drive torque change factor will be described as an example.

That is, as shown in the left rear wheel oil temperature-driving force error map of FIG. 4, when the driving torque error amount ΔLTt is generated on the plus side based on the lubricating oil temperature to1 in the left rear wheel 1RL, the left rear wheel The value indicated by the arrow in the command current map is the left rear wheel drive torque correction amount ΔLT. In this case, as shown on the lower side of FIG. 4, the current value A corresponding to the torque command value tTm is corrected to be lowered. That is, the torque command current map showing the relationship between the torque command value tTm and the current value A shown on the lower side of FIG. 4 is obtained from the current value characteristic indicated by the dotted line used at that time, and the left rear wheel drive torque correction amount ΔLT. Only shift as shown by the solid line in the figure. As a result, the driving torque error amount ΔLTt at the lubricating oil temperature To1 can be reduced.

Similarly, in the right rear wheel 1RR shown in the right rear wheel oil temperature-driving torque error map in FIG. 4, the right rear wheel driving torque correction amount ΔRT is generated on the plus side at the lubricating oil temperature to2. In this case, the command current map shown on the lower side of FIG. 4 is minus the right rear wheel drive torque correction amount ΔRT from the current value characteristic shown by the dotted line used at that time to the current value characteristic shown by the solid line in FIG. Shift to the side.
In the first embodiment, the correction of the current value A is performed based on the total driving torque error amounts ΔLTtotal and ΔRTtotal instead of the driving torque error amounts ΔLTt and ΔRTt.
Further, in the first embodiment, since the control of the torque command value tTm is executed independently for the left and right drive units WD, the correction is also performed on the left and right rear wheel command currents on the lower side of FIG. As shown in the map, each is performed independently.

Next, correction when the total drive torque error amounts ΔLTtotal and ΔRTtotal of the left and right rear wheels 1RL and 1RR are outside the control limit value range in steps S6 and S7 will be described.
In step S6, when the total drive torque error amounts ΔLTtotal and ΔRTtotal of the left and right rear wheels 1RL, 1RR are larger than the control limit torque upper limit value Tmax, the process proceeds to step S11. In step S11, correction is performed so that the corrected left and right drive torque error amounts ΔLTt, ΔRTt are the same while the drive torque correction amounts ΔLT, ΔRT are set to the control limit torque upper limit value Tmax.

A specific example will be described in which the left rear wheel total drive torque error amount ΔLTtotal exceeds the control limit torque upper limit value Tmax.
In this case, the left rear wheel drive torque correction amount ΔLT limits the correction amount to the control limit torque upper limit value Tmax.
That is, ΔLT = Tmax.
On the other hand, the right rear wheel drive torque correction amount ΔRT is obtained by the following equation (2) so that the corrected left and right drive torque error amounts ΔLTt and ΔRTt are the same.
ΔRT = ΔRTtotal− (ΔLTtotal−Tmax) (2)
That is, for the left rear wheel 1RL, even if drive torque correction is performed with the left rear wheel drive torque correction amount ΔLT (= control limit torque upper limit value Tmax), a drive torque error amount ΔLTt of (ΔLTtotal−Tmax) remains. Therefore, the right rear wheel drive torque correction amount ΔRT is set so that the same drive torque error amount ΔRTt remains after the correction limited to the Tmax for the right rear wheel 1RR.

Contrary to the above, when the right rear wheel total drive torque error amount ΔRTtotal exceeds the control limit torque upper limit value Tmax, ΔRT = Tmax is set. Further, the left rear wheel drive torque correction amount ΔLT is expressed by the following equation (3) so that the corrected drive torque error amount ΔLTt becomes the same value as the corrected drive torque error amount ΔRTt of the right rear wheel 1RR. Set.
ΔLT = ΔLTtotal− (ΔRTtotal−Tmax) (3)
In step S7, if the left and right rear wheel total drive torque error amounts ΔLTtotal and ΔRTtotal are smaller than the control limit torque lower limit value Tmin, the process proceeds to step S12. In this step S12, the left and right rear wheel drive torque correction amounts ΔLT, ΔRT are within the control limit value range, and the left and right drive torque error amounts are corrected to be the same.

A specific example will be described first when the left rear wheel total drive torque error amount ΔLTtotal is less than the control limit torque lower limit value Tmin.
In this case, the left rear wheel drive torque correction amount ΔLT limits the correction amount to the control limit torque lower limit value Tmin.
That is, ΔLT = Tmin.
On the other hand, the right rear wheel drive torque correction amount ΔRT is obtained by the following equation (4) so that the corrected left and right drive torque error amounts ΔLTt and ΔRTt are the same.
ΔRT = ΔRTtotal + (Tmin−ΔLTtotal) (4)
That is, for the left rear wheel 1RL, when the drive torque correction is performed by limiting the left rear wheel drive torque correction amount ΔLT = the control limit torque lower limit value Tmin, the drive torque error amount ΔLTt of (Tmin−ΔLTtotal) is negative. To the side. Therefore, the right rear wheel drive torque correction amount ΔRT is calculated by the above equation (4) so that the right rear wheel 1RR also becomes the same as the drive torque error amount ΔLTt after the correction limited to Tmin.

If the right rear wheel total drive torque error amount ΔRTtotal falls below the control limit torque lower limit value Tmin, ΔRT = Tmin, and the left rear wheel drive torque correction amount ΔLT is the same drive torque error as that of the right rear wheel 1RR. It is set by the following formula (5) so as to be an amount.
ΔLT = ΔLTtotal + (Tmin−ΔRTtotal) (5)
Further, when the drive torque correction amounts ΔLT and ΔRT are set in steps S11 and S12, the process proceeds to step S9, and the command current map is corrected based on the drive torque correction amounts ΔLT and ΔRT.

(Function)
Next, the operation of the first embodiment will be described.
In the drive torque control apparatus according to the first embodiment, the lubricating oil temperature To, the motor temperature Tmo, and the pump of the drive unit WD as drive torque change factors that cause the actual drive torque to deviate from the torque command value tTm. Lubricating oil amount Ov is detected.
Then, based on the lubricating oil temperature To, the motor temperature Tmo, and the pump lubricating oil amount Ov, the drive torque error amounts ΔLTt, ΔRTt generated between the torque command value tTm and the actual drive torque due to the respective drive torque change factors. , ΔLTm, ΔRTm, ΔLTp, ΔRTp are estimated. The above processing is based on the processing in steps S1L to S3L and steps S1R to S4R.

Further, each drive torque error amount ΔLTt, ΔRTt, ΔLTm, ΔRTm, ΔLTp, ΔRTp is added to the left and right to calculate a left rear wheel total drive torque error amount ΔLTtotal and a right rear wheel total drive torque error amount ΔRTtotal. As a result, a total driving torque error amount with respect to the torque command value tTm is estimated (steps S4L and S4R) in which the influences of the plurality of driving torque change factors are summed and canceled.

When these left rear wheel total drive torque error amount ΔLTtotal and right rear wheel total drive torque error amount ΔRTtotal exceed the necessity determination threshold value, correction is necessary between the torque command value tTm and the actual drive torque. It is determined that a large amount of drive torque error has occurred (step S5). If the left rear wheel total drive torque error amount ΔLTtotal and the right rear wheel total drive torque error amount ΔRTtotal do not exceed the necessity determination threshold value, both drive torque correction amounts ΔLT and ΔRT are set to 0 (step S10).

If it is determined that correction is necessary, it is determined whether the left rear wheel total drive torque error amount ΔLTtotal and the right rear wheel total drive torque error amount ΔRTtotal corresponding to the basic correction amount are within the control limit value range. To do. If the corrected control amount is within the range of the control limit value, the total drive torque error amounts ΔLTtotal, ΔRTtotal are corrected as the drive torque correction amounts ΔLT, ΔRT, and when the control limit value is exceeded, Correction is performed with the drive torque correction amounts ΔLT and ΔRT as control limit values.

Regarding the correction for limiting each of the drive torque correction amounts ΔLT and ΔRT to the control limit value, a case where the upper limit is used will be described first.
In this case, one of the drive torque correction amounts ΔLT and ΔRT is limited to the control limit torque upper limit value Tmax. By limiting the correction amount to the control limit torque upper limit value Tmax in this way, a drive torque error amount remaining between the torque command value tTm is also generated on the other wheel side, and the left and right rear wheels 1RL. , 1RR so that the drive torque error amount becomes equal.

Specifically, for example, in the left rear wheel 1RL, when the left rear wheel drive torque correction amount ΔLT is limited to the control limit torque upper limit value Tmax, after the correction, the control limit is determined from the left rear wheel total drive torque error amount ΔLTtotal. A drive torque error amount that is the amount obtained by subtracting the torque upper limit value Tmax remains.
Therefore, the right rear wheel drive torque correction amount ΔRT is not the right rear wheel total drive torque error amount ΔRTtotal, but is a value obtained by subtracting the remaining drive torque error amount (ΔLTtotal−Tmax). A drive torque error amount similar to that of the rear wheel 1RL is generated.

Further, when one of the total driving torque error amounts ΔLTtotal and ΔRTtotal is less than the control limit torque lower limit value Tmin, the correction amount is increased to the control limit lower limit value to perform correction. In this case, the driving torque error amount remains in the torque command value tTm and the actual driving torque by raising the correction amount. Therefore, the other drive wheel is corrected so that the same drive torque error amount occurs.

Specifically, for example, in the left rear wheel 1RL, when the left rear wheel drive torque correction amount ΔLT is limited to the control limit torque lower limit value Tmin, after the correction, the control limit is determined from the left rear wheel total drive torque error amount ΔLTtotal. A drive torque error amount that is an amount obtained by subtracting the torque lower limit value Tmin is generated in reverse.
Therefore, the right rear wheel drive torque correction amount ΔRT is not the right rear wheel total drive torque error amount ΔRTtotal, but is a value obtained by adding the remaining drive torque error amount (ΔLTtotal−Tmin). A drive torque error amount similar to that of the rear wheel 1RL is generated.
Note that initial variation correction amounts α and β generated due to variations at the time of manufacture are finally added to the drive torque correction amounts ΔLT and ΔRT.

As described above, in the left and right rear wheels 1RL and 1RR, by correcting so that no error occurs between the torque command value tTm and the actual drive torque (estimated value), or the same amount of error occurs on the left and right. In the left and right rear wheels 1RL, 1RR, an unintended drive torque difference can be prevented from occurring.
That is, during straight running, it is possible to prevent a vehicle behavior problem such as a single flow of the vehicle that is not intended by the driver by preventing a difference in actual driving torque between the left and right rear wheels 1RL and 1RR.

Also, even when different torque command values tTm are given to the left and right rear wheels 1RL and 1RR due to vehicle attitude control, etc., whether the torque command value tTm and the actual driving torque are corrected independently in the left and right directions. The error between the two is corrected so as to be equal on the left and right. Thus, even when different torque command values tTm are given to the left and right rear wheels 1RL, 1RR, it is possible to perform correction so that the torque command value tTm does not deviate from the actual drive torque. That is, when the left-right torque difference between the actual drive torque of the left drive unit WD and the actual drive torque of the right drive unit WD is not an error between the target drive torque and the actual drive torque in the left and right drive units WD, WD. Correction can be performed so as to approach the left-right torque difference.

(Effect of Embodiment 1)
In the torque detection device of the first embodiment, the effects listed below can be obtained.
1) The drive torque control apparatus of Embodiment 1 is
A left-side drive unit WD and a right-side drive unit WD that are mounted on the vehicle in a pair on the left and right sides and that drive the left and right rear wheels 1RL and 1RR by the electric motor 3,
A vehicle controller 11 as torque control means for independently controlling at least one of left and right drive torques of the electric motor 3;
As a first detection means for detecting the lubricating oil temperature To, the motor temperature Tmo, and the pump lubricating oil amount Ov as left driving torque change factors that cause an error between the target driving torque and the actual driving torque in the left driving unit WD. Oil temperature sensor 18, motor temperature sensor 19 and drive signal from pump P,
As second detection means for detecting the lubricating oil temperature To, the motor temperature Tmo, and the pump lubricating oil amount Ov as the right driving torque change factors causing an error between the target driving torque and the actual driving torque in the right driving unit WD. Oil temperature sensor 18, motor temperature sensor 19 and drive signal from pump P,
The left-right torque difference between the actual drive torque of the left drive unit WD and the actual drive torque of the right drive unit WD based on the detection values To, Tmo, Ov of the first detection means and the second detection means Is output to at least one of the electric motors 3 of both drive units WD and WD so as to approach the left-right torque difference when there is no error between the target drive torque and the actual drive torque in the left and right drive units WD and WD. A portion of the vehicle controller 11 that performs the processing of the flowchart of FIG. 3B as correction means for correcting the torque command value tTm to be
It is characterized by having.
In the first embodiment, the actual drive torque of the left drive unit WD is based on a drive torque change factor that causes an error between the target drive torque and the actual drive torque, such as a change in the state of the drive unit WD or a change in the environment. So that the left and right torque difference between the right drive unit WD and the actual drive torque of the right drive unit WD approaches the left and right torque difference when there is no error between the target drive torque and the actual drive torque in the left and right drive units WD and WD. The torque command value tTm is corrected. Therefore, even when different torque command values tTm are intentionally given to the left and right drive wheels, such as during vehicle attitude control, the drive torque error amount of the actual drive torque with respect to the torque command value tTm can be reduced. .
Therefore, it is possible to execute correction that suppresses the drive torque error amount of the actual drive torque with respect to the torque command value tTm even in cases other than straight traveling.
Further, since the left and right target drive torques are the same during straight running, the above correction can reduce the difference in the amount of drive torque error between the left and right drive wheels. As a result, it is possible to prevent a vehicle behavior failure such as a single flow of the vehicle not intended by the driver.

2) The drive torque control device of the first embodiment is
In the portions where the processes of steps S1L to S4L and S1R to S4R are performed as the drive torque error amount estimation means, the drive torque error amount characteristic which is the characteristic of the drive torque error amount with respect to the drive torque change factor is shown in FIGS. The map is set in advance as a map, and the drive torque error amount is estimated based on the drive torque error amount characteristic and the detected value.
Thus, the estimation of the drive torque error amount is performed because the estimation of the drive torque error amount is performed based on the characteristics of the drive torque error amount with respect to the preset drive torque change factor and the detected value of the drive torque change factor. It is possible to simplify. As a result, it is possible to improve the in-vehicle performance while suppressing the calculation load.

3) The drive torque control apparatus of the first embodiment is
The portion that performs the processing of steps S5 to S20 as the correcting means is characterized in that correction is executed when the amount of driving torque error is larger than a preset necessity determination threshold value (step S5).
As described above, when the drive torque error amount is smaller than the necessity determination threshold value, the correction is not executed. For this reason, for example, it is possible not to execute correction for a minute driving torque error amount that may occur even during normal straight traveling depending on the road surface condition, and the control load can be reduced accordingly.

4) The drive torque control apparatus of Embodiment 1 is
The detecting means detects a plurality of driving torque change factors (lubricating oil temperature To, motor temperature Tmo, pump lubricating oil amount Ov),
The part that performs the processing of steps S1L to S4L and S1R to S4R as the drive torque error amount estimation means estimates the drive torque error amount for each drive torque change factor, adds the drive torque error amounts, and adds up the total drive torque error amount. ΔLTtotal, ΔRTtotal are obtained,
The portion that performs the processing of steps S5 to S20 as the correction means is characterized in that the correction is executed based on the total drive torque error amounts ΔLTtotal and ΔRTtotal.
Thus, in order to estimate the drive torque error amount between the torque command value tTm and the actual drive torque based on a plurality of drive torque change factors, the estimation is based on one drive torque change factor. The estimation accuracy can be improved. Accordingly, the correction accuracy of the driving torque can be improved.
In addition, by detecting the lubricating oil temperature To of the left and right drive units WD and WD, respectively, the drive torque change based on the drive resistance of the drive portion due to the difference in the lubricating oil temperature To can be detected for each of the left and right drive units WD and WD. Can be estimated.
Similarly, by detecting the motor temperature Tmo of the left and right drive units WD and WD, respectively, the drive torque change due to the difference of the motor temperature Tmo can be estimated by each of the drive units WD and WD.
Similarly, by detecting the pump lubricant oil amount Ov of the left and right drive units WD and WD, respectively, the drive torque change due to the difference in the lubrication performance due to the difference in the pump lubricant oil amount Ov is estimated in each of the drive units WD and WD. can do.

5) The drive torque control device of Embodiment 1
The part that performs the processing of steps S5 to S20 as the correction means is that the total drive torque error amounts ΔLTtotal and ΔRTtotal corresponding to the correction amount of the torque command value tTm based on the drive torque error amount are preliminarily set on one of the left and right drive units WD. When the set control limit value is exceeded, one of these drive torque correction amounts ΔLT, ΔRT is limited within the range of the control limit value (control limit torque upper limit value Tmax, control limit torque lower limit value Tmin), Based on the drive torque error amount [(ΔLTtotal or ΔRTtotal) −Tmax], [Tmin− (ΔLTtotal or ΔRTtotal)] remaining due to this limitation, both drive units have the same drive torque error amount in both drive units WD. Correct the torque command value tTm for WD. It is characterized in.
When the drive torque error amount between the torque command value tTm and the actual drive torque exceeds the control limit, the control exceeding the control limit value is performed by limiting the drive torque correction amounts ΔLT and ΔRT within the control limit range. It is possible to suppress problems caused by the execution of.
In addition, by limiting the correction amount in this way, the drive unit WD on the limited side may not be able to sufficiently suppress the drive torque error amount. In this case, by performing the correction so that the left and right drive torque error amounts are the same, only the drive torque error amount of one drive unit WD that does not limit the correction is significantly reduced. It is possible to prevent the drive torque error amounts from becoming different.

6) The drive torque control apparatus of Embodiment 1
In the portion that performs the processing of steps S5 to S20 as correction means, initial variation correction amounts α and β corresponding to the initial variation error of the actual drive torque with respect to the torque command value tTm in the left and right drive units WD and WD are input in advance. In the correction, initial variation correction amounts α and β are added.
The driving torque error amount of the actual driving torque with respect to the torque command value tTm includes, in addition to the driving torque change factor, those due to initial variation errors in the manufacturing process such as manufacturing variations and assembly errors.
Therefore, by detecting this initial variation error and adding it, the amount of torque error between the torque command value tTm and the actual driving torque caused by the initial variation can be suppressed, and the correction control accuracy can be further improved. Can do.

(Other embodiments)
Next, a torque detection device according to another embodiment will be described.
Since the other embodiment is a modification of the first embodiment, the same reference numerals as those in the first embodiment are assigned to the same components as those in the first embodiment, and the description thereof is omitted. Only the differences will be described.

(Embodiment 2)
The drive torque control apparatus according to the second embodiment is different from the first embodiment in the content of the setting process of each drive torque correction amount ΔLT, ΔRT. That is, in the first embodiment, correction is performed so as to eliminate the error between the torque command value tTm and the actual drive torque on the left and right sides, but in the second embodiment, only the side on which the left and right drive torque error amounts are large is corrected. This is an example in which correction is made to match the amount of drive torque error on the smaller side. That is, even if there is an error amount between the torque command value tTm and the actual drive torque on the left and right, there is no problem as long as the drive torque error amount is the same.

FIG. 7 shows a calculation example of the drive torque error amount and the correction amount based on the lubricating oil temperature To in the left and right drive units WD.
That is, in the second embodiment, when the drive torque error amounts ΔLTt and ΔRTt are calculated as in steps S1L and S1R of the first embodiment, the difference ΔLRt (= ΔLTt−ΔRTt) between them is calculated.
When the difference ΔLRt between the drive torque error amounts ΔLTt and ΔRTt exceeds the necessity determination threshold shown in step S5 of the first embodiment, the current characteristic map on the side where the absolute value of the drive torque error amount is larger Is corrected by the left rear wheel drive torque correction amount ΔLT corresponding to the difference ΔLRt. In contrast to the example shown in FIG. 7, when the absolute value of the right rear wheel drive torque error amount ΔRTt is larger, the difference ΔLRt is used as the right rear wheel drive torque correction amount ΔRT to reduce the error amount. To the side.
Further, when a plurality of factors are used as the drive torque change factors as in the first embodiment, the difference ΔLRt may be the difference between the total drive torque error amounts ΔLTtotal and ΔRTtotal. Further, as in the first embodiment, initial variation correction amounts α and β may be added to both total drive torque error amounts ΔLTtotal and ΔRTtotal, respectively.

Therefore, even in the second embodiment, the same effect can be obtained based on the configuration described in the first embodiment and described in 1), 2), 3), 4), and 6).

The drive torque control device of the present invention has been described based on the embodiments. However, the specific configuration is not limited to these embodiments, and the invention according to each claim of the claims is described. Design changes and additions are allowed without departing from the gist.
For example, in the embodiment, the drive unit is applied to an electric vehicle that drives the left and right rear wheels. However, the drive wheels driven by the drive unit and the number of wheels are not limited to this, and can be applied not only to driving left and right front wheels but also to driving four or more wheels.
Further, in the embodiment, the lubricating oil temperature, the motor temperature, and the pump lubricating oil amount are shown as the driving torque change factors, but the factors are not limited to these. For example, in addition to using at least one of these as a driving torque change factor, other factors may be used. As other factors, the voltage of the current supplied to the electric motor, the current value, the battery SOC, the amount of lubricating oil in the unit, or the like can be used.
In the embodiment, the driving torque error amount estimating means calculates the driving torque error amount for the driving torque change factor based on the map. However, the driving torque error amount estimating means is calculated by other means such as an arithmetic expression. Also good.
Further, in the embodiment, an example in which the initial variation error amount is added to the correction of the driving torque error has been shown. However, based on this initial variation error amount, the current value characteristic with respect to the torque command value is corrected in advance. Also good.
In the embodiment, the drive torque of the electric motor is controlled independently on the left and right, but only one of the target drive torques of both motors is increased or decreased independently of the target drive torque. Control may be performed.
In the embodiment, the correction unit estimates the torque command value based on the drive torque error amount estimated by the drive torque error estimation amount estimation unit. The torque command value may be corrected directly from the torque change factor. In this case, for example, in the example as shown in FIG. 4, the relationship between the oil temperature and the command current map is obtained in advance, and the command current map is directly corrected from the detected value of the oil temperature, so that the drive torque error is calculated from the oil temperature. It is possible to correct the driving torque without obtaining the amount. In this case, as in the second embodiment, in both drive units, correction is performed only for the drive unit whose detected value is larger on the side where the error occurs, and the error amount between the two drive units is reduced. You may make it reduce.
In the embodiment, the example of correcting the command current map of the basic target drive torque has been described. However, the command value itself may be corrected. For example, during posture control, a value obtained by adding and subtracting posture control torque ΔT to the basic target drive torque may be corrected.
Further, in the embodiment, the example in which the error between the actual drive torque output from the drive unit and the torque command value for obtaining the actual drive torque is corrected has been described. However, the output torque of the motor and the output torque thereof are illustrated. You may make it correct | amend the difference | error of the torque command value for obtaining this.

Cross-reference of related applications

This application claims priority based on Japanese Patent Application No. 2013-140254 filed with the Japan Patent Office on July 4, 2013, the entire disclosure of which is fully incorporated herein by reference.

Claims

A left-side drive unit and a right-side drive unit, which are mounted on the vehicle in pairs on the left and right sides, and drive left and right drive wheels by a motor;
Torque control means for independently controlling at least one of the left and right driving torques of the motor;
First detecting means for detecting a left driving torque change factor that causes an error between the target driving torque and the actual driving torque in the left driving unit;
Second detection means for detecting a right drive torque change factor that causes an error between the target drive torque and the actual drive torque in the right drive unit;
Based on the detection values of the first detection means and the second detection means, a left-right torque difference between the actual drive torque of the left drive unit and the actual drive torque of the right drive unit is determined in the left and right drive units. Correction means for correcting a torque command value to be output to at least one of the motors of both drive units so as to approach a left-right torque difference when there is no error between the target drive torque and the actual drive torque;
A drive torque control device comprising:
The drive torque control device according to claim 1,
Drive torque error amount estimation means for estimating a drive torque error amount of the actual drive torque with respect to the torque command value based on a detection value of the detection means;
The correction means corrects the torque command value output to at least one of the motors of both drive units so that the drive torque error amount estimated by the drive torque error amount estimation means decreases. Torque control device.
The drive torque control device according to claim 2,
The driving torque error amount estimation means is preset with a driving torque error amount characteristic that is a characteristic of the driving torque error amount with respect to the driving torque change factor, and based on the detected value and the driving torque error amount characteristic, A drive torque control device that estimates a drive torque error amount.
In the drive torque control device according to claim 2 or 3,
The drive torque control apparatus, wherein the correction means performs the correction when the drive torque error amount is larger than a preset necessity determination threshold value.
The drive torque control device according to any one of claims 2 to 4,
The drive torque control device characterized in that the drive torque change factor includes a temperature of a lubricating liquid for lubricating a drive torque transmission mechanism provided between the motor and the drive wheel.
The drive torque control device according to any one of claims 2 to 5,
The drive torque control device, wherein the drive torque change factor includes a temperature of the motor.
The drive torque control device according to any one of claims 2 to 6,
The drive torque control device according to claim 1, wherein the drive torque change factor includes a supply amount of a lubricating liquid for lubricating a drive torque transmission mechanism between the motor and the drive wheels.
The drive torque control device according to any one of claims 2 to 7,
The detection means detects a plurality of driving torque change factors,
The driving torque error amount estimation means estimates the driving torque error amount for each driving torque change factor, and adds each driving torque error amount to obtain a total driving torque error amount,
The drive torque control apparatus characterized in that the correction means executes the correction based on the total drive torque error amount.
The drive torque control device according to any one of claims 2 to 8,
When the correction amount of the torque command value based on the drive torque error amount exceeds a preset control limit value on one of the left and right drive units, the correction means The correction amount is limited within the range of the control limit value, and the other drive unit has the drive torque error amount equal to the drive torque error amount after the limit of the one drive unit. The correction amount is set to the drive torque control device.
The drive torque control device according to any one of claims 1 to 9,
The torque control means executes yaw moment control that determines the target drive torque of at least one of the left and right drive units to control the yaw moment of the vehicle using the torque command value corrected by the correction means. A drive torque control device characterized by that.