Method for controlling propulsion of a heavy-duty vehicle

Patent metadata

Field	Value
Publication number	US-12208799-B2
Application number	US-202118569547-A
Country	US
Kind code	B2
Filing date	Jun 14, 2021
Priority date	Jun 14, 2021
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

A method for controlling propulsion of a heavy-duty vehicle, where the heavy-duty vehicle comprises a differential drive arrangement arranged in connection to a drive axle with a left wheel and a right wheel is provided. The method includes determining a nominal shaft slip corresponding to a desired wheel force to be generated by the drive axle wheels, wherein the nominal shaft slip is indicative of a difference between a current vehicle velocity and a vehicle velocity corresponding to the shaft speed, determining a difference between a speed of the left wheel and a speed of the right wheel, adjusting the nominal shaft slip in dependence of a magnitude of the wheel speed difference to a target shaft slip, and controlling the shaft speed based on the target shaft slip.

First claim

The invention claimed is:

1. A method for controlling propulsion of a heavy-duty vehicle, where the heavy-duty vehicle comprises a differential drive arrangement arranged in connection to a drive axle with a left wheel and a right wheel, the method comprising
determining a nominal shaft slip corresponding to a desired wheel force (Fx) to be generated by the drive axle wheels, wherein the nominal shaft slip is indicative of a difference between a current vehicle velocity (v x ) and a vehicle velocity corresponding to the shaft speed (ω0),
determining a difference between a speed (ω1) of the left wheel and a speed (ω2) of the right wheel,
adjusting the nominal shaft slip in dependence of a magnitude of the wheel speed difference to a target shaft slip,
wherein the target shaft slip is smaller than the nominal wheel slip by an amount determined as a function of the magnitude of the wheel speed difference, and
controlling the shaft speed (ω0) based on the target shaft slip.

2. The method according to claim 1 , wherein the target shaft slip is obtained by multiplying the nominal shaft slip by a reduction factor α≤1, where the reduction factor α decreases with the magnitude of the wheel speed difference.

3. The method according to claim 2 , where

1
α

=

min
⁡
(

max
⁡
(

max
⁡
(

ω
⁢
1

,

ω
⁢
2

)

-

min
⁡
(

ω
⁢
1

,

ω
⁢
2

)

Δ
max

-
1

,

1
.
0

)

,

2
.
0

)

and where the target shaft slip λ T relates to the nominal shaft slip λ 0 as
λ T =αλ 0 ,

Δ max represents a largest possible value of the difference max(ω1, ω2)−min(ω1, ω2), max(a1, a2) represents a maximum value between a1 and a2, and min(b1, b2) represents a minimum value between b1 and b2.

4. The method according to claim 1 , where the difference between the speed of the left wheel and the speed of the right wheel is adjusted based on a vehicle path curvature and/or on a vehicle steering angle.

5. The method according to claim 1 , comprising configuring the target shaft slip equal to the nominal shaft slip if the magnitude of the difference between the speed of the left wheel and the speed of the right wheel is below a pre-determined threshold.

6. The method according to claim 1 , where the target shaft slip is adapted according to a bandwidth constraint, where the bandwidth constraint is smaller for a decreasing target shaft slip compared to an increasing target shaft slip.

7. The method according to claim 1 , where the target shaft slip is adapted such that neither of the speed of the left wheel and the speed of the right wheel exceeds a wheel slip limit configured in dependence of the nominal shaft slip.

8. The method according to claim 1 , comprising triggering a service brake intervention procedure in case the magnitude of the difference between the speed of the left wheel and the speed of the right wheel exceeds a split-m condition threshold.

9. The method according to claim 1 , where shaft slip is defined as

λ
0

=

K
⁢

ω
0

-

v
x

max
⁡
(

❘
"\[LeftBracketingBar]"

K
⁢

ω
0

❘
"\[RightBracketingBar]"

,

❘
"\[LeftBracketingBar]"

v
x

❘
"\[RightBracketingBar]"

)

where K represents a conversion factor between axle speed ω 0 and vehicle velocity v x , such that Kω 0 =v x at zero wheel slip for both wheels and at equal wheel speeds, and max(a1, a2) represents a maximum value between a1 and a2.

10. The method according to claim 1 , where a relationship between the nominal shaft slip and the desired wheel force is given by an inverse tire model, the method comprising initially obtaining this inverse tire model.

11. The method according to claim 1 , comprising controlling the shaft speed based on the target shaft slip by adjusting the shaft speed to obtain the target shaft slip.

12. The method according to claim 1 , comprising controlling the shaft speed based on the target shaft slip by adjusting the shaft

Assignees

• Volvo Truck Corp

Inventors

• Salif Ramadan
• Lägnert Viktor
• Bora Teodoro

Classifications

• B60W2710/18

  Braking system · CPC title

• B60W2710/1038

  Output speed · CPC title

• B60W2520/30

  Wheel torque · CPC title

• B60W2520/28

  Wheel speed · CPC title

• B60W2520/266

  Slip values between left and right wheel · CPC title