DE102023100523A1 - Air suspension system and method for its operation and monitoring - Google Patents

Abstract

The present invention relates to an air spring system and a method for operating and monitoring an air spring unit, comprising an air spring unit and a control unit, wherein the air spring unit is installed in addition to a vehicle suspension or as a vehicle suspension in the chassis of a vehicle, wherein the control unit has a memory and a signal unit and a processor, wherein the signal unit is designed to receive and send sensor data and control signals, wherein the processor is designed to process sensor data and/or control signals, as well as parameters stored in the memory and to generate control signals from these, wherein the control signals are provided for controlling a valve unit and/or for output to a status display.

Description

The present invention relates to an air spring system for use in a motor vehicle and a method for its operation and monitoring.

Air spring systems for use in motor vehicles are already known from the state of the art. Air springs are arranged between moving parts of a motor vehicle chassis, for example a handlebar and the frame, where they perform a cushioning and vibration-damping function. The air spring systems known from the state of the art often have the problem that moisture in the air spring system causes actuators of the air spring system to corrode or freeze, particularly in winter. A great deal of effort is therefore usually made to regulate the moisture in the air spring system in order to be able to guarantee the operational reliability of the air spring. In particular, additional heating systems or air drying systems are required for air springs known from the state of the art in order to prevent damp actuators from freezing in the pneumatic control of the air springs. There are still deficits in the operationally reliable control of the known air spring systems and a great deal of effort is required to allow or prevent certain functions of the air spring control depending on the operating state of the vehicle. This in turn requires a large number of sensors and control elements, which makes the complexity of the air suspension systems known from the state of the art very high and also the weight is very high due to the large number of necessary wiring.

The object of the present invention is to provide an air spring system and a method for operating and monitoring an air spring system, which ensures a high level of operational reliability while keeping the complexity of the air spring system as low as possible.

This object is achieved with an air spring system according to claim 1, as well as a method for operating an air spring system according to one of claims 11 and 13.

According to the invention, an air spring system comprises an air spring unit and a control unit, wherein the air spring unit is installed in addition to a vehicle suspension or as a vehicle suspension in the chassis of a vehicle, wherein the control unit has a memory and a signal unit and a processor, wherein the signal unit is designed to receive and send sensor data and control signals, wherein the processor is designed to process sensor data and/or control signals, as well as parameters stored in the memory and to generate control signals from these, wherein the control signals are provided for controlling a valve unit and/or for output to a status display. The basic components of the air spring system are, on the one hand, an air spring unit, which in particular comprises the pneumatic operating means for filling and controlled emptying of the air spring, as well as the air spring and its rolling piston and fastening geometry itself. On the other hand, the air suspension system comprises a control unit which has at least one memory, a signal unit and a processor and which is connected to a status display in order to output operating parameters of the air suspension system and/or to preferably receive commands from a user of the air suspension system. Furthermore, the control signals generated by the control unit are used to control a valve unit which in particular regulates the air supply and air discharge to the air spring bellows of the air spring unit. The control unit regulates the pressure in the air spring bellows of the air spring unit via the valve unit and thus sets the spring characteristics of the vehicle suspension on the one hand and the level position, in particular the height level of the frame relative to the movable part of the chassis to which the vehicle wheel is attached. In order to enable the control unit to automatically set the correct air spring pressure depending on the vehicle condition, in particular the load, the driving speed and/or other parameters measured in the area of the chassis, corresponding parameters are stored in the memory of the control unit, which are compared by the processor of the control unit with the measured sensor data in order to generate corresponding control signals from this. In order to receive the corresponding sensor data, the control unit has a signal unit, which is in particular an interface for data processing of various measurement signals. In a particularly preferred embodiment, the air spring system is an additional air suspension which, in addition to a suspension installed as standard in a vehicle, is installed between the moving parts of the chassis and in particular enables at least additional support in the event of a high load or a controlled change in height on the chassis. Such additional air suspensions are usually used in mobile homes or light commercial vehicles in order to adapt the standard chassis to a higher vehicle weight and in particular to achieve certain comfort settings, such as raising or lowering and improved cornering behavior of the vehicle.

The air spring unit particularly preferably has a valve unit with at least one bellows valve, the bellows valve being actuated by means of a coil and an ammeter being provided which measures the electrical current in the coil, the control unit being designed to receive the sensor data from the ammeter and to determine an operating state or an error state of the bellows valve from this sensor data. The valve unit has at least one bellows valve, preferably at least two bellows valves, which open or close the flow channel in and out of the air spring. Such bellows valves are usually switched electrically, i.e. a coil generates a magnetic field when a voltage is applied, which in turn displaces an actuating body with a valve piston in order to open or close a flow channel. A frequently occurring problem with the valve units known from the prior art is that the moisture which inevitably condenses from the air with which the air spring is operated freezes, particularly in winter outside temperatures, and thus blocks the bellows valve. Within the scope of the present invention, the operational capability of the bellows valve is to be monitored and, if a fault condition is detected, the valve is to be heated up via the coil that is already present, in such a way that, in particular, freezing of the valve can be reversed. An essential aspect of this preferred embodiment of the present invention is therefore that no additional valve heating is required, but that the coil of a bellows valve is used, on the one hand, to determine the operational status and, on the other hand, to heat the bellows valve. To determine whether the bellows valve is working properly, the temporal progression of the current intensity of the current flowing through the coil of the bellows valve is determined in particular by an ammeter. A blocked bellows valve can not only be caused by freezing, but lack of lubrication and corrosion, for example, can also lead to a bellows valve not switching. In order to determine a current intensity progression that indicates a fault condition of the bellows valve, the temporal progression or the increase in the current intensity is temporarily stored, for which the control unit in particular has the memory. During a valve switching process, i.e. while an electrical voltage is switched on to actuate the coil of the bellows valve, the control unit records the current determined by the ammeter and stores this temporarily in memory. If the course of the current over time does not correspond to a standard profile of a current curve that is also temporarily stored in memory, the control unit then determines that the bellows valve is in a faulty state. The advantage of the present invention is that, regardless of the cause of the bellows valve being blocked, its faulty state can be reliably determined by monitoring the temporal course of the current in the coil of the bellows valve. In addition, no further sensors are required in the valve unit to determine the operation or faulty state. If the faulty state is determined, the control unit is designed in particular to issue a warning to the status display of the air suspension system, which can be located, for example, in the driver's compartment of the vehicle or on a mobile device. On the other hand, the control unit can automatically activate a heating voltage, which achieves electrical heating of the coil and thus also of the surrounding areas of the bellows valve. In particular, if freezing of moisture in the bellows valve is the cause of the bellows valve being blocked, this blockage can be released again.

Furthermore, the control unit is preferably designed to determine the error state when a monotonic course of the current flowing through the coil is measured. In the event that the valve switches normally, the movement of the actuator relative to the coil usually results in a kink in the curve of the current intensity, which is caused in particular by the self-induction in the coil. In the event that the bellows valve is blocked and cannot move, i.e. the error state, this kink in the curve of the current intensity is missing and a so-called monotonic course of the current intensity is present. Another possible anomaly of the current characteristic of a bellows valve can be, for example, a non-increasing current intensity, which indicates a short circuit or cable break.

The valve unit particularly preferably has at least one temperature sensor, the control unit being designed to receive the sensor data from the temperature sensor and to compare it with data stored in the memory, the processor being designed to activate a heating voltage only when the temperature falls below the temperature stored in the memory, which generates a heating current in the coil of the bellows valve. In addition to monitoring the current intensity, the control unit preferably receives sensor data from at least one temperature sensor, which is attached in the immediate vicinity of or in the bellows valve. The control unit can process the data from the temperature sensor before a heating voltage is triggered in order to decide, based on limit temperatures stored in the memory, whether the blocked valve could actually have been caused by freezing. For example, if the temperature sensor shows a valve temperature of significantly more than 0 - 5 °C, a Freezing of the valve is unlikely to be the cause of the blockage. In this case, the control unit is therefore preferably designed not to trigger any heating voltage, but rather to simply display the error on the status display with a corresponding recommendation for the user. Furthermore, by monitoring the sensor data from the temperature sensor, the control unit can prevent the bellows valve from overheating when the heating voltage is switched on by deactivating the heating voltage again in good time.

Furthermore, the control unit is advantageously designed to apply a heating voltage to the coil when a fault condition occurs, the heating voltage being active for a predefined period of time or depending on the current profile measured in the ammeter or depending on a temperature measured in the area of the valve unit. The control unit is advantageously designed to operate a relay circuit which activates or deactivates a heating voltage with a high voltage. The heating voltage can preferably be generated via a separately secured circuit which is independent of the actuation circuit. In this way, damage to the electrical actuators provided for the normal actuation of the bellows valve due to the higher voltage and resulting current intensity of the heating current can be prevented.

The heating voltage is preferably greater than an actuation voltage provided for actuating the bellows valve, the heating voltage preferably being 1.1 to 3 times the maximum actuation voltage of the bellows valve. In particular, in order to ensure the safety of the air suspension system while the vehicle is driving, the present invention provides that the heating voltage can heat up as quickly as possible and thus defrost a blocked bellows valve as quickly as possible. For this purpose, the heating voltage is advantageously greater than the usual actuation voltage provided for actuating the bellows valve. It has been shown that a voltage which is 1.1 to 3 times, particularly preferably 1.1 to 2 times, the normal actuation voltage can achieve reliable and rapid heating of a bellows valve blocked by freezing. In particular, an increased heating current and the electrical heating of the bellows valve generated by this are achieved by an increased nominal voltage which is applied to the bellows valves. The nominal voltage is preferably doubled. In a preferred embodiment, the voltage for actuating the valves is 6V, while the voltage for generating the heating current is in an overload range of 6V to 12V, particularly preferably 12V.

It is also preferred that a height sensor is provided which is attached between two movable parts of the chassis and transmits a height signal to the signal unit, the control unit being designed to calculate and store the time profile of the height signal, the processor being designed to assign the measured time profile of the height signal to a specific operating state of the vehicle based on parameters stored in the memory. In order to further increase the operational reliability of the air suspension system, it is particularly provided that the control unit records the time profile of the height signal of a height sensor and uses this to determine a specific operating state of the vehicle. In the context of the present invention, an operating state is defined as, for example, driving on uneven ground, driving on a new road surface, driving at a certain speed, the position of the vehicle while loading or unloading is taking place or, for example, the position of the vehicle while people in the vehicle are walking back and forth and thus causing a weight shift. The advantage of the present invention is that in order to determine the various operating states of the vehicle, only the close monitoring of the values output by one or more height sensors is required, and thus in particular no additional speed signals from the vehicle's wheel suspension need to be processed. Each operating state of a specific vehicle thus produces a specific temporal progression, in particular specific amplitudes and frequencies, of the signal output by the height sensor. The comparison of this measured and recorded height signal with characteristic curves stored in the memory of the control unit thus allows a conclusion to be drawn about the current operating state of the vehicle. The control unit is designed to allow or prevent certain actuation processes on the air suspension system depending on the operating state determined. For example, the control unit does not allow the user of the air suspension system to make manual changes to the height level while the vehicle is driving quickly, while the automatic correction of the vehicle's height level when cornering is permitted by the control unit and preferably carried out automatically. It is understood that, when the vehicle is stationary, the automatic correction of the angle of inclination is usually not activated, while the manual height change or leveling of the vehicle can be carried out.

The parameters stored in the memory contain in particular the amplitudes and frequencies of the height change of a chassis of a certain vehicle type. It has been shown in the context of the present invention that certain signal patterns of the height signal represent a reliable indication of the presence of certain operating states. For example, an altitude signal determined in a time window of 60 seconds with at least 20 amplitudes that exceed a certain limit value shows that the operating state "drive" is present. Furthermore, a combination of certain operating states can also be determined, such as the operating state "drive" with a simultaneous impairment due to crosswind, which can be recognized by a difference in height on the left and right sides of the vehicle. The control unit is preferably equipped with a specific set of instructions, which is stored in the memory, for each of the reliably ascertainable operating states of the vehicle in order to be able to trigger corresponding countermeasures if there is a threat to the operational safety of the vehicle.

Furthermore, a parameterization module is preferably provided and the control unit has an interface for interaction with the parameterization module, wherein the parameterization module contains a preset set of commands and/or vehicle-specific parameters for controlling the control unit, wherein the parameterization module can be controlled via the status display and/or is at least partially installed on a mobile device which is wirelessly connected to the interface. To improve the adaptation of the control unit to a specific vehicle type and thus to improve the operational reliability of this vehicle type, the air spring system has a parameterization module. The parameterization module is particularly preferably equipped with its own memory which interacts with the memory of the control unit, whereby information can be transferred from the memory of the parameterization module to that of the control unit. The parameterization module thus allows the universal use of the air spring system in different vehicle types, since the greatest possible operational reliability of the air spring system for a specific vehicle type can be achieved with an adapted set of parameters. The parameterization module therefore preferably refines the decisions of the control unit by, for example, specifying certain basic states of a height sensor, a temperature sensor or the switching current for a bellows valve to match a certain vehicle type. In addition, the parameterization module also allows the display of certain operating parameters of the vehicle and in particular of the air suspension system on the status display or on an external, mobile device. The parameterization module can, for example, be installed in a hybrid manner, both in the memory of the control unit and also on a smartphone, in such a way that certain operating parameters and warnings can be output both on the status display in the vehicle and on an external device, such as a smartphone, and a user can then give an appropriate response, preferably a command to the control unit.

Furthermore, the control unit is preferably designed to continuously output the measured values and determined operating states of the vehicle relating to the air suspension system on the status display and/or on the parameterization module described above. The control unit is therefore advantageously designed to output live data on the operating state of the air suspension system on the status display in the vehicle or on an external module, such as the parameterization module described above. In addition to increased operational safety for the user of the vehicle, this also allows fleet monitoring, for example by means of a signal transmitted via a mobile data connection, which shows transport companies, for example, free capacity in their commercial vehicles in order to be able to better coordinate short-term deliveries.

1. a) Bereitstellen einer Steuereinheit und eines Höhensensors, wobei die Steuereinheit einen Speicher und eine Signaleinheit und einen Prozessor aufweist und wobei der Höhensensor zwischen zwei beweglichen Teilen des Fahrwerkes befestigt ist, die relative Lage der Teile des Fahrwerks zueinander misst und ein Höhensignal an die Signaleinheit überträgt;
2. b) Empfangen und Speichern des zeitlichen Verlaufes des Höhensignals in der Steuereinheit;
3. c) Vergleich des gemessenen Verlaufes des Höhensignals mit im Speicher hinterlegten, charakteristischen Höhensignalverläufen;
4. d) Bestimmen eines Betriebszustandes des Fahrzeuges, abhängig vom Vergleich des gemessenen Verlaufes des Höhensignals mit im Speicher hinterlegten, charakteristischen Höhensignalverläufen;
5. e) Ausgabe des Betriebszustandes an der Zustandsanzeige und/oder erlauben oder unterbinden bestimmter Steuersignale der Steuereinheit in Abhängigkeit vom Betriebszustand des Fahrzeuges.

According to the invention, a method for operating an air spring system is provided, comprising the steps:

1. a) providing a control unit and a height sensor, wherein the control unit has a memory and a signal unit and a processor and wherein the height sensor is attached between two movable parts of the chassis, measures the relative position of the parts of the chassis to each other and transmits a height signal to the signal unit;
2. b) Receiving and storing the temporal progression of the altitude signal in the control unit;
3. c) Comparison of the measured course of the height signal with characteristic height signal courses stored in the memory;
4. d) determining an operating state of the vehicle, depending on the comparison of the measured course of the altitude signal with characteristic altitude signal courses stored in the memory;
5. e) Output of the operating status on the status display and/or allow or prohibit certain control signals from the control unit depending on the operating status of the vehicle.

The method according to the invention for operating an air suspension system is characterized in that only the temporal progression of a height signal needs to be determined and recorded in order to gain comprehensive information about the operating status of the vehicle. By comparing the recorded temporal progression of the height signal with characteristic signal progressions stored in the memory of the control unit, the control unit can make the optimal settings for certain operating states of the vehicle in order to improve the operational reliability of the air suspension system. Furthermore, by outputting a critical operating state on the status display, a user of the vehicle can be informed in good time about a potential danger, which can significantly improve the operational reliability of the vehicle.

The characteristic height signal curves stored in the memory advantageously contain in particular the amplitudes and frequencies of the height change of a chassis of a certain vehicle type. The characteristic height signal curves stored in the memory of the control unit also define the time windows within which certain limit values are considered in order to be able to provide an indication of a certain operating state of the vehicle. For example, a standard cycle of 60 seconds can be used to determine the presence of certain amplitudes and frequencies of the height signal within these 60 seconds, whereby the predetermined characteristic height signal curves are also defined within a period of 60 seconds. It goes without saying that the control unit can also be designed to monitor the height signal in parallel with another, shorter cycle in order to be able to recognize acute danger situations more quickly in particular and to react to them. Even if, within the scope of the present invention, the control unit preferably only monitors the signal of a height sensor in order to determine certain operating states, the control unit can also be designed to process the other signals on the operating state of a vehicle that are already known in the prior art. For example, the speed value of the respective wheels of the vehicle, which is usually required by an ABS, can also be received and processed in the control unit of the air suspension system according to the present invention.

1. a) Bereitstellen einer Steuereinheit und einer Ventileinheit, wobei die Steuereinheit einen Speicher und eine Signaleinheit und einen Prozessor aufweist und wobei die Ventileinheit zumindest ein Balgventil aufweist;
2. b) wobei die Steuereinheit das Balgventils mit einer Betätigungsspannung ansteuert und den zeitlichen Verlauf von durch ein Amperemeter ermittelten Stromstärke-Sensordaten im Speicher speichert und der Prozessor aus den Stromstärke-Sensordaten einen Stromverlauf berechnet;
3. c) Vergleich des errechneten Stromverlaufes mit im Speicher hinterlegten Daten;
4. d) Bestimmen eines Einsatzzustandes oder eines Fehlerzustandes und Ausgabe an eine Zustandsanzeige;
5. e) wobei für den Fall eines Fehlerzustandes die Steuereinheit automatisch oder nach manueller Bestätigung eine Heizspannung aktiviert.

Furthermore, a method for operating and monitoring a valve unit is provided, comprising the steps:

1. a) providing a control unit and a valve unit, wherein the control unit has a memory and a signal unit and a processor and wherein the valve unit has at least one bellows valve;
2. b) wherein the control unit controls the bellows valve with an actuating voltage and stores the time course of current sensor data determined by an ammeter in the memory and the processor calculates a current course from the current sensor data;
3. c) Comparison of the calculated current curve with data stored in the memory;
4. d) determining an operational state or an error state and outputting it to a status indicator;
5. e) in the event of a fault condition, the control unit activates a heating voltage automatically or after manual confirmation.

Preferably as a sub-routine of the previously described method for operating and monitoring an air spring system, a method for operating and monitoring a valve unit of such an air spring system is provided according to the invention. The control unit, which carries out the method for operating the air spring system and monitoring in particular the height signals, can also monitor and ensure the operation of a valve unit of the air spring system in a further, parallel routine. The advantage of the method for operating and monitoring the valve unit proposed according to the invention is that while the bellows valve is being switched, the temporal progression of the current in the coil of the bellows valve is determined using only an ammeter and is recorded in the memory of the control unit over a certain period of time in order to obtain an indication of whether the bellows valve is working properly. In the preferred case that the circuit that applies a voltage to the bellows valve is located within the control unit, no external measuring sensors are required, but the ammeter can be integrated into the control unit, which reduces its susceptibility to errors. In a preferred embodiment of the method, the processor of the control unit determines the time course of the current intensity of the electric current flowing through the coil of the bellows valve and compares this with characteristic courses stored in the memory, which represent proper operation or a fault condition. Depending on the settings on the air spring system, the processor of the control unit can be designed to automatically activate a heating voltage or an output can be made on the status display, whereupon a user of the vehicle can manually activate a heating voltage.

Preferably, the valve unit has at least one temperature sensor which measures the temperature in the area of the bellows valve and transmits it to the signal unit, wherein in the event that the temperature measured in the area of the bellows valve exceeds a limit value stored in the memory, the processor does not trigger a heating voltage or causes the heating voltage to be switched off. As already described above, in addition to monitoring the current intensity curve, the control unit preferably receives sensor data from at least one temperature sensor which is attached in the immediate vicinity of or in the bellows valve.

• 1 - Eine schematische Ansicht einer Ausführungsform eines erfindungsgemäßen Luftfedersystems;
• 2 - eine teilweise geschnittene Ansicht einer bevorzugen Ausführungsform einer erfindungsgemäßen Ventileinheit;
• 3 - Ansichten zweier Beispiele des Stromstärkeverlaufes bei der Betätigung eines Balgventils; und
• 4 - Beispiele verschiedener charakteristischer Höhensignalverläufe.

Further advantages and features of preferred embodiments of the present invention will become apparent from the following description with reference to the attached figures. They show:

• 1 - A schematic view of an embodiment of an air spring system according to the invention;
• 2 - a partially sectioned view of a preferred embodiment of a valve unit according to the invention;
• 3 - Views of two examples of the current intensity curve when operating a bellows valve; and
• 4 - Examples of different characteristic height signal curves.

The schematic view of 1 shows an air spring system with a control unit 2, which is designed to control an air spring system 1. The control unit has a memory 21, a signal unit 22 and a processor 23. The control unit 2 preferably also has an interface 24 for communication with a status display 8 and/or a parameterization module 25. The signal unit 22 is designed in particular for receiving various sensor data and for this purpose has a large number of slots to which various sensors and measuring devices can be connected to the control unit 2. In this preferred embodiment, two ammeters 7 are connected to the signal unit, which measure the current strength of the actuating currents flowing through the coils 52 of two bellows valves 5. Furthermore, at least one temperature sensor 6 is installed in the valve unit 4 and connected to the signal unit 22. According to a preferred embodiment of the invention, the processor 23 of the control unit 2 monitors the sensor data of the ammeter 7 and preferably also of the at least one temperature sensor 6 and compares them with values stored in the memory 21 in order to draw conclusions about the presence of an operating state E (see 3 right) or an error condition F (see 3 left).

Furthermore, a height sensor 9 is preferably provided, which transmits a height signal H to the signal unit 22, which is processed by the processor 23 and stored as a profile over time. The measured height signal profile is compared by the processor 23 with characteristic height signal profiles (a) - (e) stored in the memory 21 in order to draw conclusions about the presence of a certain operating state of the vehicle. The height signal is advantageously a voltage signal, the height of which represents a certain relative position of the moving parts of a vehicle's chassis. In other words, a certain suspension state of the chassis triggers a certain height signal H with a defined voltage. Furthermore, a parameterization module 25 is preferably provided, which serves to adapt the characteristic parameters and parameter profiles, which are stored in the memory 21 of the control unit 2, to a certain vehicle type or to certain types of use of the vehicle. The parameterization module 25 is advantageously installed on a mobile device 10 and is connected to the interface 24 by means of wireless communication. Alternatively or additionally, the parameterization module 25 is integrated entirely or partially in the control unit 2 and can be controlled via the status display 8. The status display 8 is advantageously a display which is installed in the cockpit of the vehicle and has buttons and/or a touch screen function and thus allows the input of control commands to the control unit 2.

2 shows a sectional view of a preferred embodiment of a valve unit 4 for use in an air spring unit 1 according to the invention. The valve unit 4 has at least one bellows valve 5, which in turn has at least one coil 52 and a valve piston 54. In the embodiment of 2 three such bellows valves 5 are installed. The coil 52 is supplied with electrical current in order to generate a magnetic force on the valve piston 54, which displaces it relative to the coil 52 and thus switches the bellows valve 5. Preferably, at least one ammeter 7 is provided, which measures the current flowing through the coil 52 and transmits this information to the signal unit 22 of the control unit 2. Furthermore, a large number of temperature sensors 6 are installed in the area of the bellows valves 5, which are advantageously designed as thermocouples and transmit temperature measurements in the form of voltages to the signal unit 22.

3 shows on the left side a monotonous current intensity curve in the sense of the present invention, which indicates that the valve piston 54 does not move relative to the coil 52 despite the voltage being applied and the electric current flowing through the coil 52. This current intensity curve thus indicates a fault state F in which the bellows valve 5 does not open or close properly. The right diagram of 3 shows a current intensity curve which has a characteristic kink (arrow) indicating that the bellows valve 5 is closing or opening properly, which is assumed to be an indication of an operating condition E.

1. (a) Stehendes Fahrzeug, Aussteigen, Einsteigen;
2. (b) Fahrt, ebener Fahrbahnbelag;
3. (c) langsame Fahrt auf unebenem Boden;
4. (d) Stand, Laufen im Fahrzeug;
5. (e) Stehendes Fahrzeug, Motor an

4 finally, it shows various characteristic height signal profiles, i.e. the course of the height signal H over time. These characteristic height signal profiles are advantageously stored in the memory 21 of the control unit 2 and are compared by the processor 23 with the currently measured height signal H. The following characteristic height signal profiles are provided as examples, which represent certain operating states of the vehicle:

1. (a) Stationary vehicle, alighting, boarding;
2. (b) driving, level road surface;
3. (c) driving slowly on uneven ground;
4. (d) standing, walking in the vehicle;
5. (e) Stationary vehicle, engine on

List of reference symbols:

1

Air spring unit

2

Control unit

21

Storage

22

Signal unit

23

processor

24

interface

25

Parameterization module

4

Valve unit

5

Bellows valve

52

Kitchen sink

54

Valve piston

6

Temperature sensor

7

ammeter

8th

Status display

9

Altitude sensor

10

mobile device

E

Operational condition

F

Error condition

H

Altitude signal

Claims (14)

Air spring system, comprising an air spring unit (1) and a control unit (2), wherein the air spring unit (1) is installed in addition to a vehicle suspension or as a vehicle suspension in the chassis of a vehicle, wherein the control unit (2) has a memory (21) and a signal unit (22) and a processor (23), wherein the signal unit (22) is designed to receive and send sensor data and control signals, wherein the processor (23) is designed to process sensor data and/or control signals, as well as parameters stored in the memory (21) and to generate control signals from these, wherein the control signals are provided for controlling a valve unit (4) and/or for output to a status display (8). Air suspension system according to Claim 1 , comprising a valve unit (4) with at least one bellows valve (5), wherein the bellows valve (5) is actuated by means of a coil (52) and an ammeter (7) is provided which measures the electrical current in the coil (52), wherein the control unit (2) is designed to receive the sensor data of the ammeter (7) and to determine an operating state (E) or an error state (F) of the bellows valve (5) from this sensor data. Air suspension system according to Claim 2 , wherein the control unit (2) is designed to detect the fault condition (F) when a monotonic course of the current flowing through the coil (52) is measured. Air suspension system according to one of the Claims 2 or 3 , wherein the valve unit (4) has at least one temperature sensor (6), wherein the control unit (2) is designed to receive the sensor data of the temperature sensor (6) and to compare them with data stored in the memory (21), wherein the processor (23) is designed to activate a heating voltage only when the temperature falls below the temperature stored in the memory. Air suspension system according to one of the Claims 2 until 4 , wherein the control unit (2) is designed to, in the event of a fault condition (F), the coil (52) to be subjected to a heating voltage, wherein the heating voltage is active over a predefined period of time or depending on the current curve measured in the ammeter (7) or depending on a temperature measured in the region of the valve unit. Air suspension system according to one of the Claims 2 until 5 , wherein the heating voltage is greater than a voltage provided for actuating the bellows valve (5), wherein the heating voltage is preferably 1.1 to 3 times, particularly preferably 1.1 to 2 times the maximum actuating voltage of the bellows valve. Air spring system according to one of the preceding claims, wherein a height sensor (9) fastened between two movable parts of the chassis transmits a height signal (H) to the signal unit (22), wherein the control unit (2) is intended to calculate and store the temporal progression of the height signal (H), wherein the processor (23) is designed to assign the measured temporal progression of the height signal (H) to a specific operating state of the vehicle based on parameters stored in the memory (21). Air suspension system according to Claim 7 , wherein the parameters stored in the memory (21) contain in particular the amplitudes and frequencies of the height change of a chassis of a specific vehicle type. Air spring system according to one of the preceding claims, wherein a parameterization module (25) is provided and the control unit (2) has an interface (24) for interaction with the parameterization module (25), wherein the parameterization module (25) contains a preset set of commands and/or vehicle-specific parameters for controlling the control unit (2), wherein the parameterization module (25) can be controlled via the status display (8) and/or is at least partially installed on a mobile device (10) which is wirelessly connected to the interface (24). Air suspension system according to one of the preceding claims, wherein the control unit (2) is designed to display the measured values and determined operating states of the vehicle relating to the air suspension system on the status display (8) and/or on the parameterization module (25) according to Claim 9 to be issued continuously. Method for operating an air spring system, comprising the steps: a) providing a control unit (2) and a height sensor (9), the control unit (2) having a memory (21) and a signal unit (22) and a processor (23), and the height sensor (9) being attached between two movable parts of the chassis, measuring the relative position of the parts of the chassis to one another and transmitting a height signal (H) to the signal unit (22); b) receiving and storing the temporal course of the height signal (H) in the control unit (2); c) comparing the measured course of the height signal (H) with characteristic height signal courses stored in the memory (21); d) determining an operating state of the vehicle, depending on the comparison of the measured course of the height signal (H) with characteristic height signal courses stored in the memory (21); e) Output of the operating state on the status display (8) and/or allowing or blocking certain control signals from the control unit (2) depending on the operating state of the vehicle. Procedure according to Claim 11 , wherein the characteristic height signal curves stored in the memory (21) contain in particular the amplitudes and frequencies of the height change of a chassis of a specific vehicle type. Method for operating and monitoring a valve unit (4) of an air spring system, comprising the steps: a) providing a control unit (2) and a valve unit (4), wherein the control unit (2) has a memory (21) and a signal unit (22) and a processor (23) and wherein the valve unit (4) has at least one bellows valve (5); b) where the control unit (2) controls the bellows valve (5) with an actuating voltage and stores the time profile of current sensor data determined by an ammeter (7) in the memory and the processor (23) calculates a current profile from the current sensor data; c) comparing the calculated current profile with data stored in the memory (21); d) determining an operating state (E) or an error state (F) and outputting it to a status display (8); e) in the event of an error condition (F), the control unit (2) activates a heating voltage automatically or after manual confirmation. Procedure according to Claim 13 , wherein the valve unit (4) has at least one temperature sensor (6) which measures the temperature in the Area of the bellows valve (5) and transmits it to the signal unit (22), wherein in the event that the temperature measured in the area of the bellows valve (5) exceeds a limit value stored in the memory (21), the processor (23) does not trigger a heating voltage or causes the heating voltage to be switched off.

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