# US 12,005,900 B2 · Vehicle controllability during trailer backup operations

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- Number: US 12,005,900 B2
- Document ID: US12005900B2
- Status: Granted
- Kind: B2
- Application number: 17/653,942
- Filed: 2022-03-08
- Published: 2023-09-14
- Granted: 2024-06-11
- Earliest claimed: 2022-03-08
- Assignees: GM Global Technology Operations LLC
- Applicants: GM Global Technology Operations LLC
- Inventors: Avesta Goodarzi; Utkarsh Saini
- Web page: https://patentgrep.com/patent/US12005900B2

## CPC

- B60W 30/18036: {Reversing}
- B60D 1/14: Draw-gear or towing devices characterised by their type
- B60D 1/245: {for facilitating push back or parking of trailers}
- B60D 1/62: involving supply lines, electric circuits or the like
- B60W 10/18: including control of braking systems
- B60W 40/105: Speed
- B60W 2300/14: Tractor-trailers, i.e. combinations of a towing vehicle and one or more towed vehicles, e.g. caravans; Road trains
- B60W 2520/10: Longitudinal speed
- B60W 2520/22: Articulation angle, e.g. between tractor and trailer
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60D: VEHICLE CONNECTIONS

## Abstract

Systems, methods, and apparatus are provided in a vehicle to reduce the likelihood of a trailer jackknife condition. The method includes: receiving trailer profile information; receiving a dynamic vehicle steering angle (δ) and dynamic hitch articulation angle (θ) while the vehicle is moving in a reverse direction; continuously calculating a maximum safe vehicle speed (vmax) at which to proceed in reverse without jackknifing based on the trailer profile information, the δ, the θ, a predetermined safe time to jackknife (TTJ_ne), and a maximum hitch articulation angle (θJK); comparing a current vehicle longitudinal speed (v) to the vmax; automatically generating a speed correction signal to cause the vehicle to slow down below the vmax when the v exceeds the vmax; and sending the speed correction signal to a vehicle motion control system to instruct the vehicle motion control system to reduce the v below the vmax.

## Claims

### Claim 1

A trailer backup system in a vehicle for automatically adjusting vehicle dynamics while the vehicle is hitched to a trailer to reduce a likelihood of a trailer jackknife occurring, the trailer backup system comprising a controller, the controller configured to:
receive trailer profile information, wherein the trailer profile information comprises a vehicle wheelbase distance (L), a vehicle's rear axle to hitch point distance (d), and a trailer rear axle distance (D);
receive a dynamic vehicle steering angle (δ) and dynamic hitch articulation angle (θ) while the vehicle is moving in a reverse direction;
continuously calculate a maximum safe vehicle speed (vmax) at which to proceed in reverse without jackknifing based on the trailer profile information, the δ, the θ, a predetermined safe time to jackknife (TTJ_ne), and a maximum hitch articulation angle (θJK), wherein the TTJ_ne is a calibratable time value that specifies a safety margin in time before a jackknife condition would be predicted to occur;
wherein:
V
max
=
L
TTJ_ne
·
E
⁢
ln
⁡
(
|
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
|
)
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
E
=
A
2
+
B
2
-
C
2
,
d
⁢
θ
d
⁢
t
=
V
L
[
tan
⁢
δ
⁡
(
1
+
d
D
⁢
cos
⁢
θ
)
+
L
D
⁢
sin
⁢
θ
]
,
If dθ/dt is positive, then θJK=θJK, and If dθ/dt negative, then θJK=−θJK;
compare a current vehicle longitudinal speed (v) to the vmax;
automatically generate a speed correction signal to cause the vehicle to slow down below the vmax when the v exceeds the vmax; and
send the speed correction signal to a vehicle motion control system to instruct the vehicle motion control system to reduce the v below the vmax, wherein the vehicle motion control system controls appropriate vehicle actuators to reduce the v.

### Claim 2 (depends on 1)

The trailer backup system of claim 1, wherein the controller is further configured to:
calculate a time to jackknife (TTJ(θ)) based on the trailer profile information, the δ, the θ, and the v; and
automatically generate a brake control signal to cause the vehicle to brake to a complete stop when the TTJ(θ) is less than a predetermined minimum safe time to jackknife (TTJmin), wherein TTJmin is a calibratable value.

### Claim 3 (depends on 2)

The trailer backup system of claim 2, wherein:
TTJ
⁡
(
θ
)
=
L
VE
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
and
⁢
E
=
A
2
+
B
2
-
C
2
.

### Claim 4 (depends on 1)

The trailer backup system of claim 1, wherein the controller is further configured to:
calculate a time to jackknife (TTJ(θ)) based on the trailer profile information, the δ, the θ, and the v; and
automatically generate a brake control signal to cause the vehicle to brake to a complete stop when the TTJ(θ) is less than a predetermined minimum safe time to jackknife (TTJmin), wherein TTJmin is a calibratable value.

### Claim 5 (depends on 4)

The trailer backup system of claim 4, wherein:
TTJ
⁡
(
θ
)
=
L
VE
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
and
⁢
E
=
A
2
+
B
2
-
C
2
.

### Claim 6

A vehicle having a trailer backup system for automatically adjusting vehicle dynamics while the vehicle is hitched to a trailer to reduce a likelihood of a trailer jackknife condition, the vehicle comprising:
a propulsion actuator;
a braking actuator;
a vehicle motion control system for controlling vehicle and trailer motion; and
a controller configured to:
receive trailer profile information, wherein the trailer profile information comprises a vehicle wheelbase distance (L), a vehicle's rear axle to hitch point distance (d), and a trailer rear axle distance (D);
receive a dynamic vehicle steering angle (δ) and dynamic hitch articulation angle (θ) while the vehicle is moving in a reverse direction;
continuously calculate a maximum safe vehicle speed (vmax) at which to proceed in reverse without jackknifing based on the trailer profile information, the δ, the θ, a predetermined safe time to jackknife (TTJ_ne), and a maximum hitch articulation angle (θJK), wherein the TTJ_ne is a calibratable time value that specifies a safety margin in time before a jackknife condition would be predicted to occur; compare a current vehicle longitudinal speed (v) to the vmax;
automatically generate a speed correction signal to cause the vehicle to slow down below the vmax when the v exceeds the vmax;
send the speed correction signal to the vehicle motion control system to instruct the vehicle motion control system to reduce the v below the vmax, wherein the vehicle motion control system controls the braking actuator and the propulsion actuator to reduce the v;
calculate a time to jackknife (TTJ(θ)) based on the trailer profile information, the δ, the θ, and the v; and
automatically generate a brake control signal to cause the vehicle to brake to a complete stop when the TTJ(θ) is less than a predetermined minimum safe time to jackknife (TTJmin), wherein TTJmin is a calibratable value, wherein
TTJ
⁡
(
θ
)
=
L
VE
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
and
⁢
E
=
A
2
+
B
2
-
C
2
.

### Claim 7 (depends on 6)

The vehicle of claim 6, wherein:
V
max
=
L
TTJ_ne
·
E
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
E
=
A
2
+
B
2
-
C
2
,
d
⁢
θ
dt
=
V
L
[
tan
⁢
δ
⁡
(
1
+
d
D
⁢
cos
⁢
θ
)
+
L
D
⁢
sin
⁢
θ
]
,
If
⁢
d
⁢
θ
dt
⁢
is
⁢
positive
,
then
⁢
θ
JK
=
θ
JK
,
and
⁢
If
⁢
d
⁢
θ
dt
⁢
is
⁢
negative
,
then
⁢
θ
JK
=
-
θ
JK
.

### Claim 8 (depends on 7)

The vehicle of claim 7 wherein the controller is further configured to:
calculate a time to jackknife (TTJ(θ)) based on the trailer profile information, the δ, the θ, and the v; and
automatically generate a brake control signal to cause the vehicle to brake to a complete stop when the TTJ(θ) is less than a predetermined minimum safe time to jackknife (TTJmin), wherein TTJmin is a calibratable value.

### Claim 9 (depends on 8)

The vehicle of claim 8, wherein:
TTJ
⁡
(
θ
)
=
L
VE
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
and
⁢
E
=
A
2
+
B
2
-
C
2
.

### Claim 10

A method in a vehicle having a trailer backup system for automatically adjusting vehicle dynamics while the vehicle is hitched to a trailer to reduce a likelihood of a trailer jackknife condition, the method comprising:
receiving trailer profile information, the trailer profile information comprising a vehicle wheelbase distance (L), a vehicle's rear axle to hitch point distance (d), and a trailer rear axle distance (D);
receiving a dynamic vehicle steering angle (δ) and dynamic hitch articulation angle (θ) while the vehicle is moving in a reverse direction;
continuously calculating a maximum safe vehicle speed vmax) at which to proceed in reverse without jackknifing based on the trailer profile information, the δ, the θ, a predetermined safe time to jackknife (TTJ_ne), and a maximum hitch articulation angle (θJK), wherein the TTJ_ne is a calibratable time value that specifies a safety margin in time before a jackknife condition would be predicted to occur;
wherein:
V
max
=
L
TTJ_ne
·
E
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
E
=
A
2
+
B
2
-
C
2
,
d
⁢
θ
dt
=
V
L
[
tan
⁢
δ
⁡
(
1
+
d
D
⁢
cos
⁢
θ
)
+
L
D
⁢
sin
⁢
θ
]
,
If
⁢
d
⁢
θ
dt
⁢
is
⁢
positive
,
then
⁢
θ
JK
=
θ
JK
,
and
⁢
If
⁢
d
⁢
θ
dt
⁢
is
⁢
negative
,
then
⁢
θ
JK
=
-
θ
JK
.
comparing a current vehicle longitudinal speed (V) to the vmax;
automatically generating a speed correction signal to cause the vehicle to slow down below the vmax when the v exceeds the vmax; and
sending the speed correction signal to a vehicle motion control system to instruct the vehicle motion control system to reduce the v below the vmax, wherein the vehicle motion control system controls appropriate vehicle actuators to reduce the v.

### Claim 11 (depends on 10)

The method of claim 10, further comprising:
calculating a time to jackknife (TTJ(θ)) based on the trailer profile information, the δ, the θ, and the v; and
automatically generating a brake control signal to cause the vehicle to brake to a complete stop when the TTJ(θ) is less than a predetermined minimum safe time to jackknife (TTJmin), wherein TTJmin is a calibratable value.

### Claim 12 (depends on 11)

The method of claim 11, wherein:
TTJ
⁡
(
θ
)
=
L
VE
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
d
D
⁢
tan
⁢
δ
,
C
=
tan
⁢
δ
,
and
⁢
E
=
A
2
+
B
2
-
C
2
.

### Claim 13 (depends on 10)

The method of claim 10, further comprising:
calculating a time to jackknife (TTJ(θ)) based on the trailer profile information, the δ, the θ, and the v; and
automatically generating a brake control signal to cause the vehicle to brake to a complete stop when the TTJ(θ) is less than a predetermined minimum safe time to jackknife (TTJmin), wherein TTJmin is a calibratable value.

### Claim 14 (depends on 13)

The method of claim 13, wherein:
TTJ
⁡
(
θ
)
=
L
VE
⁢
ln
⁡
(
❘
"\[LeftBracketingBar]"
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
-
E
)
]
[
(
C
-
B
)
⁢
tan
⁢
θ
JK
2
+
(
A
+
E
)
]
⁢
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
+
E
)
[
(
C
-
B
)
⁢
tan
⁢
θ
2
+
(
A
-
E
)
]
❘
"\[RightBracketingBar]"
)
,
A
=
L
D
,
B
=
D
D
⁢
TAN
⁢
δ
,
C
=
TAN
⁢
δ
,
AND
⁢
E
=
A
2
+
B
2
-
C
2
.