# US 8,543,305 B2 · Method and device for assessing the compatability of braking systems of a vehicle combination

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- Number: US 8,543,305 B2
- Document ID: US8543305B2
- Status: Granted
- Kind: B2
- Application number: 12/451,686
- Filed: 2008-05-09
- Published: 2010-08-26
- Granted: 2013-09-24
- Earliest claimed: 2007-05-24
- Assignees: WABCO GmbH
- Applicants: Bernd Heise; Hans Holst; Udo Ronnenberg; Axel Stender; Norbert Witte
- Inventors: Bernd Heise; Hans Holst; Udo Ronnenberg; Axel Stender; Norbert Witte
- Web page: https://patentgrep.com/patent/US8543305B2

## CPC

- B60T 17/18: Safety devices; Monitoring
- B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES

## Abstract

A method and a device for assessing the compatibility of braking systems of a vehicle combination comprising a tractor and a trailer determine applied braking power (Wa) for a braking process of the trailer, and a required braking power for the braking process (Wb) of the trailer.

## Claims

### Claim 1

A method for assessing the compatibility of braking systems of a vehicle combination having a towing vehicle and a trailer vehicle, said vehicle combination including a suitably programmed control device having a memory, the method comprising the steps of (i) determining, utilizing said control device, an applied amount of braking energy from a start of a braking process of said trailer vehicle to an end of said braking process, (ii) determining, utilizing said control device, a required amount of braking energy from said start of said braking process to said end of said braking process, (iii) determining, utilizing said control device, a variable that is both a function of and a quotient formed from each of said applied amount of braking energy and said required amount of braking energy, and (iv) adjusting said braking systems of said vehicle combination based on said variable, wherein said determining of said applied amount of braking energy comprises detecting an applied braking pressure in a brake cylinder of said trailer vehicle.

### Claim 2 (depends on 1)

The method as claimed in claim 1, wherein said applied amount of braking energy is a function of at least one wheel circumferential speed of a wheel of said trailer vehicle and at least one brake cylinder pressure of a brake cylinder of said trailer vehicle.

### Claim 3 (depends on 1)

The method as claimed in claim 1, wherein said step of determining said applied amount of braking energy includes calculating said applied amount of braking energy according to the relationship:
W
aj
=
k
·
T
·
∑
i
=
1
n
⁢
(
p
Bji
-
p
A
⁢
⁢
N
)
·
v
Rji
Where:
Waj is the amount of braking energy applied by the brake cylinder of the trailer vehicle to brake a trailer wheel;
k is a constant;
T is a sampling time of the control device;
pBji is the pressure in the brake cylinder;
pAN is an application pressure; and
vRji is a circumferential speed of the wheel braked by the brake cylinder.

### Claim 4 (depends on 1)

The method as claimed in claim 1, wherein said variable is a function of said applied amount of braking energy for a plurality of braking processes, and said required amount of braking energy for said plurality of braking processes.

### Claim 5 (depends on 1)

The method as claimed in claim 1, further comprising the step of outputting said variable.

### Claim 6 (depends on 1)

The method as claimed in claim 1, further comprising the step of transmitting at least one of (i) said applied amount of braking energy and said required amount of braking energy and (ii) said variable to a receiver unit by means of a telematics interface.

### Claim 7 (depends on 1)

The method as claimed in claim 1, wherein at least one of (i) said steps of determining said applied amount of braking energy and said required amount of braking energy and (ii) said step of determining said variable is effected during a normal driving mode of said vehicle combination.

### Claim 8 (depends on 1)

The method as claimed in claim 1, wherein at least one of (i) said steps of determining said applied amount of braking energy and said required amount of braking energy and (ii) said step of determining said variable is effected automatically.

### Claim 9 (depends on 1)

The method as claimed in claim 1, wherein said step of determining said variable excludes a braking process on a roadway having a longitudinal inclination in excess of a predefined limiting value.

### Claim 10 (depends on 9)

The method as claimed in claim 9, further comprising the step of detecting said braking process on a roadway having a longitudinal inclination in excess of a predefined limiting value based on a speed gradient sensed before said braking process.

### Claim 11 (depends on 1)

The method as claimed in claim 1, further comprising the step of adjusting said braking systems of said vehicle combination as a function of said variable.

### Claim 12 (depends on 1)

The method as claimed in claim 1, further comprising the steps of storing said applied amount of braking energy and said required amount of braking energy in said control device, and presenting said applied amount of braking energy and said required amount of braking energy via an interface.

### Claim 13

A method for assessing the compatibility of braking systems of a vehicle combination having a towing vehicle and a trailer vehicle, said vehicle combination including a suitably programmed control device having a memory, the method comprising the steps of (i) determining, utilizing said control device, an applied amount of braking energy of a braking process of said trailer vehicle, (ii) determining, utilizing said control device, a required amount of braking energy of said braking process of said trailer vehicle, (iii) determining, utilizing said control device, a variable that is both a function of and a quotient formed from each of said applied amount of braking energy and said required amount of braking energy, and (iv) adjusting said braking systems of said vehicle combination based on said variable, wherein said step of determining said required amount of braking energy includes calculating said required amount of braking energy according to the relationship:
W
b
=
m
A
·
(
v
An
-
v
A
⁢
⁢
1
)
2
2
Where:
Wb is the required amount of braking energy;
mA is the mass of the trailer vehicle;
vAl is the speed of the trailer vehicle at the start of the braking process; and
vAn is the speed of the trailer vehicle after the end of the braking process.

### Claim 14

A control device suitably programmed to effect a method for assessing the compatibility of braking systems of a vehicle combination having a towing vehicle and a trailer vehicle, the method comprising the steps of (i) determining, utilizing said control device, an applied amount of braking energy from a start of a braking process of said trailer vehicle to an end of said braking process, (ii) determining, utilizing said control device, a required amount of braking energy from said start of said braking process to said end of said braking process, (iii) determining, utilizing said control device, a variable that is both a function of and a quotient formed from each of said applied amount of braking energy and said required amount of braking energy, and (iv) adjusting said braking systems of said vehicle combination based on said variable, wherein said determining of said applied amount of braking energy comprises detecting an applied braking pressure in a brake cylinder of said trailer vehicle.

### Claim 15

A method for assessing the compatibility of braking systems of a vehicle combination having a towing vehicle and a trailer, said vehicle combination including a suitably programmed control device having a memory, the method comprising the steps of:
when said vehicle combination is being braked, determining braked trailer speed at the start of braking, and storing said braked trailer speed in said control device; determining brake pressures in trailer brake cylinders and wheel speeds of trailer wheels braked by said trailer brake cylinders, and storing said brake pressures and wheel speeds in said control device;
when said vehicle combination is no longer being braked, determining unbraked trailer speed, and storing said unbraked trailer speed in said control device;
utilizing said control device, calculating an applied amount of braking energy Waj according to the relationship:
W
aj
=
k
·
T
·
∑
i
=
1
n
⁢
(
p
Bji
-
P
AN
)
·
v
Rji
Where:
k is a constant,
T is a sampling time of the control device,
pBji is the pressure in the brake cylinder,
pAN is an application pressure, and
vRji is the circumferential speed of the braked trailer wheel;
utilizing said control device, calculating a required amount of braking energy Wb according to the relationship:
W
b
=
m
A
·
(
v
An
-
v
A
⁢
⁢
1
)
2
2
Where:
mA is the mass of the trailer vehicle,
vAl is the speed of the trailer at the start of the braking process, and
vAn is the speed of the trailer after the end of the braking process;
utilizing said control device, determining a variable as both a function of and a quotient formed from said applied amount of braking energy and said required amount of braking energy; and
adjusting said braking systems of said vehicle combination based on said variable.

### Claim 16

A control device suitably programmed to effect a method for assessing the compatibility of braking systems of a vehicle combination having a towing vehicle and a trailer, the method comprising the steps of:
when said vehicle combination is being braked, determining braked trailer speed at the start of braking, and storing said braked trailer speed in said control device; determining brake pressures in trailer brake cylinders and wheel speeds of trailer wheels braked by said trailer brake cylinders, and storing said brake pressures and wheel speeds in said control device;
when said vehicle combination is no longer being braked, determining unbraked trailer speed, and storing said unbraked trailer speed in said control device;
utilizing said control device, calculating an applied amount of braking energy Waj according to the relationship:
W
aj
=
k
·
T
·
∑
i
=
1
n
⁢
(
p
Bji
-
P
AN
)
·
v
Rji
Where:
k is a constant,
T is a sampling time of the control device,
pBji is the pressure in the brake cylinder,
pAN is an application pressure, and
vRji is the circumferential speed of the braked trailer wheel;
utilizing said control device, calculating a required amount of braking energy Wb according to the relationship:
W
b
=
m
A
·
(
v
An
-
v
A
⁢
⁢
1
)
2
2
Where:
mA is the mass of the trailer vehicle,
vAl is the speed of the trailer at the start of the braking process, and
vAn is the speed of the trailer after the end of the braking process;
utilizing said control device, determining a variable as both a function of and a quotient formed from said applied amount of braking energy and said required amount of braking energy; and
adjusting said braking systems of said vehicle combination based on said variable.