Method for operating a wiper system as well as a computer program product, control unit and wiper system for vehicle windshields

Abstract

Method for operating a wiper system for vehicle windows, in particular vehicle windshields, with at least one first wiper (1) and a second wiper (2), wherein the first wiper is driven by a first motor (101) controlled by a first control unit (9), and the second wiper by a second motor (102) controlled by a second control unit (9a), wherein the first motor (101) is provided as a primary motor and the second motor (102) as a secondary motor, the method comprising: exchanging information between the first control unit (9) and the second control unit (9a), putting the second control unit into a power-saving mode for a predetermined period of time; exchanging information between the first control unit (9) and the second control unit (9a) after the expiry of a period of time which is at least as long as the predetermined period of time.

Description

[0001] Embodiments of the invention relate to a method for operating a wiper drive with a motor or a wiper system, a computer program product with program code stored on a machine-readable medium, and a control unit for a wiper drive. In particular, the invention relates to reducing the power consumption of the wiper drive or the wiper system. State of the art

[0002] Various wiper blade types and drive mechanisms are used to clean windshields on motor vehicles. Wiper blades are primarily distinguished as single-lever and double-lever wiper blades. Drive mechanisms can be categorized as direct drives or linkage drives. Even with direct drives, so-called compact linkages can be used. In double-lever wiper blades, the wiper levers, consisting of the wiper arm and wiper blade, can be driven in either the same direction or in opposite directions.

[0003] The drive mechanism for linkage-based wiper systems often uses only one wiper motor, even for two windshield wipers. In the case of a linkage drive, the rotary motion of this motor's output shaft is translated via a crank mechanism into an oscillating pivoting motion of the wiper shafts. Some wiper motors are equipped with electronics that control a reversing motion of the output shaft. This electronic control also enables wiper angle adjustment with dynamic, load-dependent angle correction and wiper speed control. Furthermore, the electronics allow for various wiper functions and positions, such as an extended park position. Generally, front wiper systems, such as reversing front wiper systems, are now designed as either single-motor or dual-motor wiper systems.

[0004] In single-motor wiper systems, one electric motor, such as a reversing electric motor, drives the wiper blades for the driver's and passenger's sides. In dual-motor wiper systems, one electric motor, such as a reversing electric motor, drives the wiper blade on the driver's side. A second electric motor, such as a reversing electric motor, drives the wiper blade on the passenger's side. Such a wiper system is known, for example, from DE 103 06 496 A1.

[0005] Dual-motor wiper systems typically include a primary (master) unit and a secondary (slave) unit. A master wiper motor control unit typically has two communication interfaces through which it communicates with the vehicle and the slave wiper motor control unit. The slave wiper motor control unit has one communication interface through which it communicates with the master wiper motor control unit. These control units and interfaces are active, among other things, for operational safety, to detect error messages and abnormal operating conditions so that such conditions can be rectified.

[0006] It is desirable to reduce the power consumption in wiper systems while fulfilling their function and, in particular, their safety requirements. Disclosure of the invention

[0007] The object of the invention is to at least partially solve the above-mentioned problems, for example with the aim of reducing the power consumption during driving operation while maintaining the full functionality of the wiper system, e.g. a front wiper system.

[0008] According to embodiments of the invention, the current consumption during the wiper system is reduced during driving without the wiper function, with diagnosis or monitoring of the operating conditions being carried out at suitable intervals.

[0009] According to one embodiment, a method for operating a wiper system for vehicle windows, in particular vehicle windshields, is provided, wherein the wiper system comprises at least a first wiper and a second wiper, the first wiper being driven by a first motor controlled by a first control unit, and the second wiper being driven by a second motor controlled by a second control unit, the first motor being designated as a primary motor and the second motor as a secondary motor. The method includes exchanging information between the first control unit and the second control unit, putting the second control unit into a power-saving mode for a predetermined period, and exchanging information between the first control unit and the second control unit after the expiration of a period that is at least as long as the predetermined period.

[0010] According to a further embodiment, a computer program product with program code stored on a machine-readable medium is provided. The computer program product is configured to carry out the method for operating a wiper system for vehicle windows, in particular vehicle windshields, wherein the wiper system comprises at least a first wiper and a second wiper, the first wiper being driven by a first motor controlled by a first control unit, and the second wiper being driven by a second motor controlled by a second control unit, the first motor being provided as a primary motor and the second motor as a secondary motor.The procedure involves exchanging information between the first control unit and the second control unit, putting the second control unit into a power-saving mode for a predetermined period of time, and exchanging information between the first control unit and the second control unit after the expiry of a period of time that is at least as long as the predetermined period of time.

[0011] According to a further embodiment, a control unit for a wiper drive, in particular a direct wiper drive, is provided. The control unit is configured to carry out the method for operating a wiper system for vehicle windows, in particular vehicle windshields, wherein the wiper system comprises at least a first wiper and a second wiper, wherein the first wiper is driven by a first motor controlled by a first control unit, and the second wiper by a second motor controlled by a second control unit, wherein the first motor is provided as a primary motor and the second motor as a secondary motor.The procedure involves exchanging information between the first control unit and the second control unit, putting the second control unit into a power-saving mode for a predetermined period of time, and exchanging information between the first control unit and the second control unit after the expiry of a period of time that is at least as long as the predetermined period of time.

[0012] According to a further embodiment, a wiper system for vehicle windows, in particular vehicle windshields, is provided. The system includes a control unit or a computer program product according to one of the embodiments of the invention. The system further includes a first wiper and a second wiper, wherein the first wiper is driven by a first motor controlled by a first control unit, and the second wiper by a second motor controlled by a second control unit, the first motor being provided as a primary motor and the second motor as a secondary motor.

[0013] Preferred embodiments and special aspects of the invention will become apparent from the dependent claims, the drawings and the accompanying description. Advantages of the invention

[0014] The embodiments described here according to the present invention make it possible to reduce or minimize the power consumption of a wiper system with the aim of saving CO2 at the vehicle level by implementing a partial or permanent activation of the power saving mode (sleep mode) of a secondary (slave) wiper motor control unit.

[0015] Furthermore, functionality, including safety-relevant functions, can be maintained.

[0016] According to one embodiment, a method for operating a wiper system for vehicle windows, in particular vehicle windshields, is provided, wherein the wiper system comprises at least a first wiper and a second wiper, the first wiper being driven by a first motor controlled by a first control unit, and the second wiper being driven by a second motor controlled by a second control unit, the first motor being designated as a primary motor and the second motor as a secondary motor. The method includes exchanging information between the first control unit and the second control unit, putting the second control unit into a power-saving mode for a predetermined period, and exchanging information between the first control unit and the second control unit after the expiration of a period that is at least as long as the predetermined period.By selecting the predetermined time duration, e.g. depending on the design of the wiper system, functionality including safety-relevant functions can be maintained, and power consumption can be reduced to a surprisingly high extent.

[0017] Driving with the front wiper activated results in a short operating time of approximately 800 hours compared to the total vehicle operating time of approximately 8500 hours (short-term operation). Despite this short-term operation, particularly given the increasing power demands of modern vehicles, it has been recognized in the embodiments of the present invention that a reduction in power consumption is possible even for short-term operation to such an extent that appropriate measures lead to a sufficient improvement. Typically, according to the embodiments described here, the system concept provides the option of partially or permanently putting the slave wiper control unit into maximum power-saving operation or power-saving mode (sleep mode).According to typical embodiments, which can be combined with the other embodiments described here, the current consumption in power-saving operation or power-saving mode is 160 µA or less, such as 10 µA to 100 µA, e.g., 80 µA. This reduces the current consumption of the entire front wiper system by up to 50% (from typically 60 mA to typically 30 mA), with the added benefit of CO2 reduction in the vehicle during driving without the wiper function.

[0018] According to further typical preferred embodiments, before the second control unit is put into power-saving mode, the exchange of information between the first and second control units is terminated for at least the predetermined duration. This ensures that the communication protocols through which the information is exchanged function without interference and that power-saving mode can be carried out as planned.

[0019] According to further typical preferred embodiments, the power-saving mode is initiated by the second control unit when the first control unit terminates the exchange of information. This allows the power-saving mode to be made available without further signals after a time defined as a limit value has elapsed without any information exchange.

[0020] According to further typical preferred embodiments, the power-saving mode of the second control unit is initiated by a signal from the first control unit and / or the power-saving mode is terminated by an activation signal from the first control unit. This ensures that the master control unit actively monitors the state of the slave control unit. This allows the state to be logged in order to document and actively control safety-relevant functions.

[0021] Typically, power-saving mode is activated for a predetermined period. Communication or information exchange is also interrupted for at least the predetermined period, but usually for a period that is at least somewhat longer than the predetermined period.

[0022] The embodiments, features, details, examples, and descriptions described here refer to primary units, devices, and components, and secondary units, devices, and components, or to master and slave, in the context of control units, motors, and similar components. The primary units, devices, and components provide the master function within the respective assembly system, and the secondary units, devices, and components provide the slave function within the respective assembly component. The terms primary and master, as well as secondary and slave, are used interchangeably here. They describe a hierarchy of devices and components, for example, for control purposes. A secondary (slave) unit is controlled by a primary (master) unit and / or has no independent resources with respect to communication protocols that it can access without the primary unit.Furthermore, for example, the master control unit of the wiper system can be considered a slave of the vehicle control system with regard to another assembly system, such as the vehicle control system.

[0023] According to further typical preferred embodiments, the wiper system is a counter-rotating wiper system and the predetermined time duration is 20 s or less, in particular 12 s or less, and furthermore in particular 10 s or less. Since monitoring of the park position of the lower wiper, typically the secondary unit, is not necessary for counter-rotating wiper systems, the predetermined time duration provided for power-saving operation (sleep mode) can be increased compared to synchronous wiper systems.

[0024] According to other typical preferred embodiments, the predetermined time duration is 500 ms or less, in particular 100 ms or less.

[0025] According to typical embodiments that can be combined with the embodiments described here, the predetermined duration for power-saving operation (sleep mode) is a parameter that is regularly used for a typical or normal operating condition. The predetermined duration can vary within the defined ranges, e.g., by prioritizing communication channels or other control functions; it can be redefined or modified within the defined ranges when certain operating conditions occur; and it can also vary in other ways in critical or other exceptional operating conditions (e.g., maintenance). However, embodiments of the present invention include operating conditions, typically normal operation, in which the predetermined duration is used in the respective areas of the operating procedure. Brief description of the drawings

[0026] Exemplary embodiments of the invention are shown in the figures and are described in more detail below. The figures show:

[0027] Fig. 1 A schematic view of a wiper system according to the embodiments described herein, comprising a primary unit and a secondary unit;

[0028] Fig. 2 a schematic view of another wiper system according to embodiments described herein, comprising a primary unit and a secondary unit;

[0029] Fig. 3 a flowchart for a method for operating a wiper system according to the embodiments described herein. Embodiments of the invention

[0030] In Fig. Figure 1 schematically depicts a preferred embodiment of a windshield wiper system with two counter-rotating wipers. This embodiment also serves to illustrate further embodiments, modifications, and configurations. The wiper system includes a driver's side (FS) wiper. 1 and a passenger-side (BS) wiper 2 up. This is due to the steering wheel. 3 displayed. The first wiper 1 It is an upper wiper. It has an upper wiper arm. 4 and an upper wiper blade 1 up. The second wiper 2 is a lower wiper and has a lower wiper arm 5 and a lower wiper blade 2 up. The first wiper and the second wiper are in Fig. 1 shown in the parked position. In the parked position shown, the wiper blades are 1 and 2The wiper blades are arranged one above the other, at least partially overlapping, in the lower area of ​​the windshield to be wiped. During the first half of a wiping cycle – the upward wipe – the upper wiper blade moves. 1 approximately in a quarter circle, while the counter-rotating lower wiper blade 2 Simultaneously (apart from any possible phase shifts between the two wipers), it performs a quarter-circle movement in opposite directions. When the wiper blades 1 and 2 Once they have reached their upper reversal positions, they change their direction of movement and, after wiping downwards, reach their lower reversal positions at the end of the wiping cycle. The lower reversal positions can be determined by the Fig. The parking position shown in Figure 1 may differ. Furthermore, modern mopping systems may also include an extended parking position and / or additional functional or service positions.

[0031] According to embodiments of the present invention, the wiper system is designed as a two-motor wiper system. Each of the two wipers is driven by a wiper module or wiper unit, with a motor. 6 or 7 , for example a reversing motor a gearbox 8 and a control unit 9 driven.

[0032] The controls for the two wiper modules are connected to a vehicle control unit as follows. 11 or connected to a wiring harness. The primary wiper module or primary wiper unit on the driver's side includes a primary control unit. 9 , which is next to the supply line for earth 12 and tension 13 , with a communication line 14 for exchanging data and commands with a vehicle control unit 11 is connected. The primary control unit 9, i.e., the master wiper motor control unit, includes two communication interfaces, one via which it communicates with the vehicle or the vehicle control unit. 11 , and a communication interface through which it communicates with the secondary control unit 9a , i.e., the slave wiper motor control unit, exchanges data and commands. In the present disclosure, data, commands, or other signals between control units are referred to as information, so that the control units, in addition to connections for a power supply, include connections and / or interfaces for information, i.e., any kind of information.

[0033] The secondary wiper module on the passenger side includes a secondary control unit. 9a , which is next to the supply lines for earth 12 and tension 13 , with a communication line 15 for exchanging data and commands with a vehicle control unit 11is connected. According to typical designs, the slave wiper motor control unit has a communication interface through which it exclusively exchanges data and commands with the master wiper motor control unit.

[0034] The slave control unit 9a is controlled by the control unit 9 The master control unit is controlled by the slave control unit. The master cyclically sends target position values ​​to the slave control unit. For example, the slave control unit responds via the same communication line. 15 each with its actual position values.

[0035] In conventional wiper systems, the communication line 15Permanently active, meaning that information (data and / or commands, such as target values, actual values, status messages, error messages, etc.) can and is constantly being exchanged. This means that these communication interfaces are permanently active during driving without the wiper function, both on the primary and secondary control units. This increases the power consumption of the slave wiper motor control unit. In this operating mode, i.e., without the wiper function, the control units serve solely for internal error reporting from the slave to the master wiper motor control unit and for monitoring the park position, whereby an unwanted deviation from the park position can also be considered an error message.

[0036] Due to the inherently reduced self-locking of the drives in dual-motor wiper systems, strong winds or a car wash can cause the wiper arms to be forced out of their parked position. For this reason, master and slave wiper motor control units continuously monitor their parked position while driving without the wiper function and activate their electric motors as needed to maintain the parked position.

[0037] However, embodiments of the present invention do not require monitoring of the park position by the secondary wiper, which is arranged below the primary wiper, in counter-rotating wiper systems, since the secondary unit is blocked by the primary unit. This is the case, for example, in Fig. Figure 1 illustrates this. For counter-rotating wiper systems and corresponding embodiments, the following operation can thus be provided as an example. The master, i.e., the primary control unit. 9It maintains communication with the vehicle. The communication of the primary control unit. 9 with the secondary control unit 9aThis setting allows the secondary control unit to be put into power-saving mode (sleep mode). The secondary control unit (slave wiper control unit) is put into power-saving mode, for example, via software. If a fault diagnosis of the secondary control unit is required, the primary control unit (master) cyclically and briefly (e.g., every 10 seconds) activates communication, thereby waking the slave for fault diagnosis. The time between activation phases can be 20 seconds or less, e.g., 12 seconds or less, according to typical embodiments. The duration of the activation phases for fault diagnosis can be, for example, 10 ms to 100 ms. According to the embodiments described here, functionality can be maintained, particularly with regard to safety regulations (e.g., ISO 26262), since a failure of the secondary wiper function on the passenger side in the park position is not safety-critical.The driver's field of vision continues to be wiped by the primary unit (master). Therefore, reduced fault diagnosis of the secondary (slave) wiper is permissible.

[0038] Furthermore, in counter-rotating wiper systems, strong winds cannot push the secondary (slave) wiper arm out of its parked position, as the primary (master) wiper arm is positioned above the secondary (slave) wiper arm in the parked position. Therefore, monitoring the parked position in the secondary wiper motor control unit is unnecessary. Consequently, permanently activating the power-saving mode (sleep mode) is permissible, even from a safety perspective. Therefore, predetermined power-saving durations of 20 seconds or less, e.g., 10 seconds or less, are possible.

[0039] Fig. Figure 2 shows a synchronous wiper system. This synchronous wiper system has essentially the same components as the one in Fig. 1. Counter-rotating wiper system shown. Only the arrangement of the wiper differs. 2 The design on the passenger side is different, so that the wiper 2 in operation has the same direction of rotation as the wiper 1 For those relating to Fig. For the sake of simplicity, a renewed description of the components is omitted in the embodiments described in section 2, and the corresponding configurations can be analogous to those described in relation to Fig. The embodiments described in 1 may be used, unless differences are explicitly described.

[0040] The Master's degree in Fig. 2, i.e., the primary control unit 9 , maintains communication with the vehicle, for example with the vehicle control unit 11 , upright. The communication of the primary control unit 9 with the secondary control unit 9aThis setting allows the secondary control unit to be put into power-saving mode (sleep mode). The secondary control unit (slave wiper control unit) is put into power-saving mode, for example, via software. If a fault diagnosis of the secondary control unit is required, the primary control unit (master) cyclically and briefly activates communication, thereby waking the slave for fault diagnosis. The time between activation phases for fault diagnosis can be 20 seconds or less for typical embodiments, e.g., 12 seconds or less. The duration of the activation phases for fault diagnosis can be, for example, 10 ms to 100 ms. According to the embodiments described here, functionality can be maintained, particularly with regard to safety regulations (e.g., ISO 26262), since a failure of the secondary wiper function on the passenger side in the park position is not safety-critical.The driver's field of vision continues to be wiped by the primary unit (master). Therefore, reduced fault diagnosis of the secondary (slave) wiper is permissible.

[0041] However, with synchronized wiper systems, strong winds or a car wash can cause the secondary (slave) wiper arm to move out of its parked position, as the primary (master) wiper arm is not positioned above the secondary (slave) wiper arm in the parked position. Therefore, monitoring of the parked position in the secondary wiper motor control unit is necessary. Continuous or prolonged activation of the power-saving mode (sleep mode) is therefore not permitted, as, for example, in car washes, leaving the parked position can lead to damage or destruction of the wiper system.

[0042] To reduce power consumption in designs with a synchronous wiper system, the secondary (slave) wiper control unit is only cyclically and briefly (e.g., every 100 ms) switched to power-saving mode. During these short periods of activity, fault diagnosis is performed and / or the park position is monitored. If necessary, the electric motor can be activated to maintain the park position. Thus, according to typical designs with a synchronous wiper system, a duration of 200 ms or less, and in particular 100 ms or less, is specified for power-saving operation.

[0043] If the parking position or the probability that the self-locking mechanism is insufficient to maintain the parking position is monitored by other means, a longer duration for power-saving operation can also be used in a parallel-running system. For example, if the speed is below a certain threshold, the vehicle control unit can transmit a longer duration for power-saving operation to the master control unit, so that durations of 20 seconds or less (e.g., 10 seconds or less) can also be used in this case.

[0044] Fig. Figure 3 shows a flowchart for a process according to embodiments of the present invention. In step 302 Information is transferred between the first control unit ( 9 ) and the second control unit ( 9a ) exchanged. In step 304The second control unit is put into power-saving mode. This lasts for a certain period of time. This duration is predetermined, but can be set differently for different operating modes, e.g., in the areas described. In step 306 Information is (again) exchanged between the first control unit ( 9 ) and the second control unit ( 9a ) exchanged after a period of time that is at least as long as the duration of the period. QUOTES INCLUDED IN THE DESCRIPTION

[0045] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0046] DE 10306496 A1

[0004] Cited non-patent literature

[0047] ISO26262

[0037] ISO26262

[0040]

Claims

[1] Method for operating a wiper system for vehicle windows, in particular vehicle windshields, with at least one first wiper ( 1 ) and a second wiper ( 2 ), wherein the first wiper is operated by a first motor ( 101 ), which is controlled by a first control unit ( 9 ) is controlled, and the second wiper is controlled by a second motor ( 102 ), which is controlled by a second control unit ( 9a ) is controlled, are driven, with the first motor ( 101 ) as a primary engine and the second engine ( 102 ) as a secondary engine, the procedure includes: exchange of information between the first control unit ( 9 ) and the second control unit ( 9a ), putting the second control unit into power-saving mode for a predetermined period of time; exchange of information between the first control unit ( 9) and the second control unit ( 9a ) after a period of time that is at least as long as the predetermined period. [2] Method according to claim 1, wherein, prior to putting the second control unit into power-saving mode, the exchange of information between the first control unit ( 9 ) and the second control unit ( 9a ) is terminated in order to avoid exchanging information for at least the predetermined period of time. [3] Method according to claim 2, wherein the power saving mode is started by the second control unit by the first control unit ceasing the exchange of information. [4] Method according to one of claims 1 to 2, wherein the power saving mode of the second control unit is started by a signal from the first control unit. [5] Method according to any one of claims 1 to 4, wherein the power saving mode is terminated by an activation signal from the first control unit. [6] Method according to any one of claims 1 to 5, wherein the wiper system is a counter-rotating wiper system and the predetermined time duration is 20 s or less, in particular 12 s or less, and furthermore in particular 10 s or less. [7] Method according to any one of claims 1 to 5, wherein the wiper system is a synchronous wiper system and the predetermined time duration is 200 ms or less, in particular 100 ms or less. [8] Computer program product comprising program code stored on a machine-readable medium for carrying out the method according to any one of claims 1 to 7 when the program is executed on a computer or a control device. [9] Control unit ( 11 , 9 , 9a ) for a wiper drive, in particular a wiper direct drive, which is programmed for use in a method according to one of claims 1 to 7. [10] Wiper system for vehicle windows, in particular vehicle windshields, comprising: a control unit according to claim 9 and / or a computer program product according to claim 8; and a first wiper ( 1 ) and a second wiper ( 2 ), wherein the first wiper is operated by a first motor ( 101 ), which is controlled by a first control unit ( 9 ) is controlled, and the second wiper is controlled by a second motor ( 102 ), which is controlled by a second control unit ( 9a ) is controlled, are driven, with the first motor ( 101 ) as a primary engine and the second engine ( 102 ) as a secondary engine.

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