AIR SPRING CONTROL SYSTEM, AIR SPRING SYSTEM, VEHICLE INCLUDING SAME, AND METHOD FOR SAME

Abstract

An air suspension control system is for a vehicle with a first and a second axle. The system has an auxiliary control unit connected to a main control unit via a data link. The auxiliary unit has a pressure sensor associated with the first axle for determining pressure measurements of the first axle as pressure sensor signals and an input for receiving height sensor signals. The input can be connected to a first height sensor on the first axle for receiving first height signals and to a second height sensor on the second axle for receiving second height signals. The auxiliary unit is adapted to transmit the first and/or second height sensor signals and/or the pressure sensor signals to the main unit. The main unit is adapted to carry out weighing for the first and/or second axle in dependence on the first and/or second height signals and/or the pressure signals.

Claims

1. An air suspension control system for a vehicle having a first axle and a second axle, the air suspension control system comprising: a main control unit for operating the air suspension control system; an auxiliary control unit connected to said main control unit via a data link; said auxiliary control unit having a pressure sensor associated with the first axle of the vehicle and configured to determine pressure measurements of the first axle as pressure sensor signals; said auxiliary control unit having an input for receiving height sensor signals; said input being connectable to a first height sensor arranged on the first axle for receiving first height measurements as first height sensor signals and to a second height sensor arranged on the second axle for receiving second height measurements as second height sensor signals; said auxiliary control unit being configured to transmit at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals to said main control unit via the data link; and, said main control unit being configured to carry out on-board weighing for at least one of the first axle and the second axle in dependence on at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals.

2. The air suspension control system of claim 1, wherein at least one of a) said input of said auxiliary control unit is configured to be connected to a further sensor in order to receive further sensor signals; and, b) said auxiliary control unit has a further input configured to be connected to the further sensor in order to receive h further sensor signals.

3. The air suspension control system of claim 1, wherein said auxiliary control unit has an output for actuating an actuator which is connectable to said output: wherein said auxiliary control unit is configured to store a function for generating control signals at the output; said main control unit is configured to at least one of call up and parameterize at least said function stored in said auxiliary control unit by transmitting commands via the data link; and, wherein said auxiliary control unit is configured to generate control signals at said output in dependence on at least one of the first height sensor signal at said input, the second height sensor signals at said input, and the pressure sensor signals.

4. The air suspension control system of claim 1, wherein said auxiliary control unit is configured to store a predefined fixed set of functions in said auxiliary control unit.

5. The air suspension control system of claim 3, wherein said auxiliary control unit is configured to receive and interpret at least one predefined fixed set of commands from said main control unit.

6. The air suspension control system of claim 3, wherein said auxiliary control unit is configured, after receiving a command sent by said main control unit and received via the data link, to transmit at least one of first height sensor signals, second height sensor signals, and pressure sensor signals to said main control unit.

7. The air suspension control system of claim 1, wherein said auxiliary control unit is arranged on the first axle of the vehicle.

8. The air suspension control system of claim 1, wherein at least one of a) the first axle of the vehicle is air-sprung; and, b) the second axle of the vehicle is steel-sprung.

9. The air suspension control system of claim 1, wherein the vehicle is a two-axle vehicle and the first axle of the vehicle is a rear axle of the vehicle and the second axle of the vehicle is a front axle of the vehicle.

10. The air suspension control system of claim 1, wherein said data link is at least one of a bus link and a CAN bus link.

11. An air suspension system which is controllable via an air suspension control system, the air suspension system comprising: a first height sensor arranged on a first axle of the vehicle and connected to an input of an auxiliary control unit for determining first height measurements; and, a second height sensor arranged on a second axle of the vehicle and connected to the input of the auxiliary control unit for determining second height measurements.

12. The air suspension system of claim 11, wherein the air suspension control system includes: a main control unit for operating the air suspension control system; wherein the auxiliary control unit is connected to the main control unit via a data link; the auxiliary control unit having a pressure sensor associated with the first axle of the vehicle and being configured to determine pressure measurements of the first axle as pressure sensor signals; wherein the input of the auxiliary control unit is configured to receive first height measurements as first height sensor signals and second height measurements as second height sensor signals; the auxiliary control unit being configured to transmit at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals to said main control unit via the data link; and, said main control unit being configured to carry out on-board weighing for at least one of the first axle and the second axle in dependence on at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals.

13. The air suspension system of claim 11 further comprising: an actuator configured to connect to the air suspension control system; said actuator being a valve drive; and, said valve drive being configured to actuate a flow through a valve opening of a valve in a continuous manner or in more than three steps, wherein the valve drive is connected to said valve opening for actuation.

14. The air suspension system of claim 13, wherein said valve drive includes a stepper motor.

15. The air suspension system of claim 12, wherein the actuator is configured to be connected to at least one output of the auxiliary control unit.

16. A vehicle comprising: a first axle; a second axle; at least one of an air suspension control system and the air suspension system of claim 11; said air suspension control system including a main control unit and an auxiliary control unit connected to said main control unit via a data link; said auxiliary control unit having a pressure sensor associated with the first axle of the vehicle and configured to determine pressure measurements of the first axle as pressure sensor signals; said auxiliary control unit having an input for receiving height sensor signals; said input of said auxiliary control unit being connectable to a first height sensor arranged on the first axle of the vehicle for receiving first height measurements as first height sensor signals and to a second height sensor arranged on the second axle of the vehicle for receiving second height measurements as second height sensor signals; said auxiliary control unit being configured to transmit at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals to said main control unit via the data link; and, said main control unit being configured to carry out on-board weighing for at least one of the first axle and the second axle in dependence on at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals.

17. The vehicle of claim 16, wherein the vehicle is a commercial vehicle or a passenger vehicle.

18. A method for operating a vehicle having a first axle and a second axle via an air suspension control system; the air suspension control system including a main control unit and an auxiliary control unit having a pressure sensor associated with the first axle and an input; the auxiliary control unit being connected to the main control unit via a data link, the method comprising: determining pressure measurements of the first axle as pressure sensor signals via the auxiliary control unit; receiving, at the input of the auxiliary control unit, first height sensor signals from a first height sensor arranged on the first axle of the vehicle and second height sensor signals from a second height sensor arranged on the second axle of the vehicle, wherein the first height sensor and the second height sensor are connectable to the input of the auxiliary control unit; transmitting at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals from the auxiliary control unit to the main control unit via the data link; and, carrying out on-board weighing for at least one of the first axle and the second axle in dependence on at least one of the first height sensor signals, the second height sensor signals, and the pressure sensor signals.

19. The method of claim 18, wherein control signals are generated at an output of the auxiliary control unit in dependence on functions which are stored in the auxiliary control unit and in dependence on commands which are sent by the main control unit to the auxiliary control unit.

20. The method as claimed in claim 18, wherein control signals are generated at an output of the auxiliary control unit in dependence on at least one of the first height sensor signals at the input, second height sensor signals at the input, and the pressure sensor signals.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The invention will now be described with reference to the drawings wherein:

[0054] FIG. 1 shows a schematic diagram of an air suspension control system and of an air suspension system having two auxiliary control units in the case of two air-sprung axles;

[0055] FIG. 2 shows a schematic diagram of an air suspension control system and of an air suspension system having two auxiliary control units in the case of an air-sprung axle and a steel-sprung axle;

[0056] FIG. 3 shows a schematic diagram of an air suspension control system and of an air suspension system having one auxiliary control unit in the case of an air-sprung axle and a steel-sprung axle; and,

[0057] FIG. 4 shows an air suspension system having an air suspension control system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] FIG. 1 shows an air suspension control system 10 and an air suspension system 26 for a vehicle 48. The air suspension control system 10 includes a main control unit 12 and two auxiliary control units 14. The auxiliary control units 14 are each connected to the main control unit 12 via a data link 16. Accordingly, the data link 16 serves to transmit data from the main control unit 12 to the auxiliary control units 14 and from the auxiliary control units 14 to the main control unit 12.

[0059] In FIG. 1, the data link 16 is represented by two individual lines, which each include, for example, a plurality of electrical or optical cables. According to another embodiment, which is not shown in FIG. 1, these two lines are not separate and there is a shared data link between the main control unit 12 and the two auxiliary control units 14 (see FIG. 2). This shared data link is preferably a bus system.

[0060] Each of the auxiliary control units 14 has two outputs 18, to each of which an actuator 20 is electrically connected. Each of the auxiliary control units 14 additionally includes two inputs 22, to each of which a sensor 24 is connected.

[0061] The air suspension control system 10 is configured in such a manner that functions in the auxiliary control units 18 are first called up via the main control unit 12 via the data link 16 and are parameterized. On the basis of these functions, output signals are then generated at the outputs 18 for the actuators 20 in dependence on the function and also on sensor data which are provided via the sensors 24 to the inputs 22 of the auxiliary control units 14. Functions are, for example, the raising or lowering of a vehicle with the air suspension control system or the tilting of the vehicle or level control during or after loading of a vehicle.

[0062] FIG. 2 shows an air suspension control system 10 and an air suspension system 26 corresponding to FIG. 1. The air suspension control system 10 likewise includes a main control unit 12 and two auxiliary control units 14, wherein the auxiliary control units 14 are connected to the main control unit 12 via a data link 16. In FIG. 2, the data link 16 is represented schematically as a single line, which includes, for example, a plurality of electrical or optical cables. The data link 16 can in this way form a shared data link 16 between the main control unit 12 and the two auxiliary control units 14, for example in the form of a bus system. The data link can, however, also include two or more individual lines.

[0063] In contrast to FIG. 1, it is shown in FIG. 2 that, of two axles 36 of the vehicle with wheels 38, only one axle 36a is air-sprung and accordingly has air-suspension bellows 40 with actuators 20. The other axle 36b is steel-sprung and accordingly has steel springs 42.

[0064] FIG. 2 shows two different types of sensors 24: On the one hand, a pressure sensor 46 is arranged in each of the auxiliary control units 14. By associating an auxiliary control unit 14 with each of the axles 36, a pressure sensor 46 is thus also associated with each of the axles 36.

[0065] Furthermore, a height sensor 44 is associated with each of the axles 36, wherein precisely one height sensor 44 is here associated with each of the auxiliary control units 14, wherein the auxiliary control unit 14 and the height sensor 44 associated therewith are in each case associated with the same axle 36.

[0066] FIG. 3 shows, in an analogous manner to FIG. 2, an air suspension control system 10 having a main control unit 12. The air suspension control system 10 according to FIG. 3 is likewise arranged on a vehicle which has an air-sprung axle 36a and a steel-sprung axle 36b. According to FIG. 3, however, an auxiliary control unit 14 is arranged only on the air-sprung axle 36a. Accordingly, a pressure sensor 44 is also associated only with the air-sprung axle 36a. However, a height sensor 44 is associated with both the air-sprung axle 36a and the steel-sprung axle 36b. The two height sensors 44 are associated with the same auxiliary control unit 14 arranged on the air-sprung axle 36a. This is possible because the auxiliary control unit 14 has two inputs 22 for height sensor data. It is, however, also possible that the two height sensors 44 are connected to the same input 22 of the auxiliary control unit.

[0067] Because there is here only one air-sprung axle 36a at which air-suspension valves 38 must be actuated via the actuators 20, one auxiliary control unit 14 is sufficient for fully controlling the air suspension of the vehicle. However, by associating the height sensor 44 of the steel-sprung axle 36b with the auxiliary control unit 14 in addition to the height sensor 44 of the air-sprung axle 36a and the pressure sensor 46 of the air-sprung axle 36a, the auxiliary control unit 14 and the main control unit 12 can evaluate the sensor data of the sensors 24, 44, 46 such that additional functions that go beyond mere air suspension can be ensured:

[0068] A deflection of the air-sprung axle 36a and/or of the steel-sprung axle 36b can be determined from the height sensor data of the height sensor 44 of the air-sprung axle 36a and/or the height sensor data of the height sensor 44 of the steel-sprung axle 36b. Determination of the deflection can be carried out by the main control unit 12 in that the height sensor data are transmitted by the auxiliary control unit 12 to the main control unit via the data link 16. The pressure sensor data can also be transmitted by the auxiliary control unit 14 to the main control unit via the data link 16. The main control unit 12 can carry out on-board weighing for the steel-sprung axle 36b on the basis of the deflection thereof and for the air-sprung axle on the basis of the pressure sensor data, which can indicate a bellows pressure in the air-suspension bellows 40.

[0069] FIG. 4 shows an air suspension system 26 which is controllable via the air suspension control system 10. The air suspension system here has an actuator 20 which is in the form of a valve drive 28. The valve drive 28 is accordingly connected to an output 18 of the auxiliary control unit 14. The valve drive 28 is part of a valve 30 and has a stepper motor 32 for actuating a valve opening 34 of the valve 30 in a continuous manner or in more than three steps.

[0070] The valve 30 is thus actuated by the auxiliary control unit 14 in such a manner that a step of the valve opening 34 which is desired is provided for the valve drive 28. The valve drive 28 then adjusts the valve opening 34 according to the desired step via the stepper motor 32. The flow through the valve 30 is thereby varied in such a manner that, for example, slow or rapid raising of a vehicle is made possible by filling a cylinder with gas, in particular air, according to the flow.

[0071] It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

LIST OF REFERENCE NUMERALS (PART OF THE DESCRIPTION)

[0072] 10 air suspension control system [0073] 12 main control unit [0074] 14 auxiliary control unit [0075] 16 data link [0076] 18 output for connection of an actuator [0077] 20 actuator [0078] 22 input for acquisition of sensor data [0079] 24 sensor [0080] 26 air suspension system [0081] 28 valve drive [0082] 30 valve [0083] 32 stepper motor [0084] 34 valve opening [0085] 36 axle [0086] 38 wheel [0087] 40 air-suspension bellows [0088] 42 steel spring [0089] 44 height sensor [0090] 46 pressure sensor [0091] 48 vehicle