Drive control of electric motors, in particular windshield wipers for motor vehicles

Abstract

TITLE: Drive control for electric motors, in particular for windshield wipers of motor vehicles Drive control (115, 120) for electric motors (125', 130') of motor vehicles, in particular for motors (125', 130') of windshield wiper arms (135, 140), designed for operation at a reduced processor clock frequency. Figure 1

Description

Title of the invention: Drive control of electric motors, in particular motor vehicle windshield wipers FIELD OF THE INVENTION

[0001] The present invention relates to a drive control for electric motors of motor vehicles, in particular windshield wiper arm drive motors. STATE OF THE ART

[0002] Such drive controls are already known.

[0003] Motor vehicles are equipped with windshield wipers to wipe the windows, in particular the windshield to remove moisture and dirt. A windshield wiper comprises a drive, a wiper arm and a wiper blade. The drive ensures the oscillating movement of the wiper arm which causes the wiper blade to pass over the window. Passenger vehicle windshields are generally equipped with two juxtaposed wipers. To avoid a mechanical connection between the arms of the two wipers, each wiper is equipped with its own drive and these drives are synchronized to avoid a collision of the wiper arms and the wiper blades and to respect the sequence of movements of the wipers. Each drive has its own control.

[0004] According to document DE 10 2009 029 457 A1, a drive control is known, in particular for controlling the drive of the windshield wipers of a motor vehicle. This document DE 10 2009 029 457 A1 describes a control system comprising a control module, a first drive control and a second drive control; the drive controls are associated with the motor that drives the windshield wiper arms. A first connection connects the control module to a first interface of the first drive control. A second connection passes from the second interface of the first drive control to the second interface of the second drive control. The control module is part of the electrical installation of the vehicle and communicates at regular intervals with the first drive control. Information is thus exchanged independently of the operating state of the first and second drives.The information exchanged concerns configuration, status and operating parameters. A first link can be part of a LIN bus (local interconnected network). The second link is part, for example, of the Carline link.

[0005] In the usual embodiment, the processor of the windshield wiper electronics operates continuously even without rain. Under these conditions, the power consumption is higher than what would be necessary.

[0006] DISCLOSURE AND ADVANTAGES OF THE INVENTION

[0007] The subject of the invention is a drive control for electric motors of a motor vehicle, in particular for driving windshield wiper arm motors, this control being characterized in that it is designed for operation at a reduced processor clock rate.

[0008] The invention also relates to a control system equipped with at least one drive control as defined above.

[0009] The invention makes it possible to reduce energy consumption.

[0010] In a conventional embodiment, the processor of the wiper electronics always operates at a fixed, predefined clock rate. As a result, the electrical energy consumption in the standby state is higher than would be necessary. As long as it is not raining, the wiper is preferably not activated. During this time, the clock rate of the processor is reduced to reduce current consumption. In this operating state, the clock rate is preferably just at a level sufficient for bus communication in the vehicle. Motor control or regulation as well as mechanical and thermal protection functions are preferably not calculated by the processor.

[0011] In addition, this reduced frequency further reduces the heat generated by the processor, which has a positive impact on temperature management.

[0012] In the case of electronically commutated wiper motors, in standby mode, the rotor position sensor is switched off. This means that there is no power supply, which reduces the quiescent current level in the wiper accordingly. To monitor the position of the wiper arm in the standby position, for example, to compensate for the shifting of the wiper arms by the circulating wind, a sensor on the output shaft is preferably sufficient.

[0013] Preferably, it is only when the wiper motor is activated that the processor clock frequency is increased and the rotor position sensor is activated.

[0014] In particular, in extended standby mode, the power consumption is lower, in direct comparison with the wiping mode activated, for example, during intervals in the case of intermittent operation.

[0015] The invention also applies to a large number of similar applications in which active operating times can be had for different states of operation with different power consumptions. This mainly concerns actuators with short operating times and long waiting times.

[0016] It is advantageous to predefine the reduced frequency of the processor clock rate to enable communication via at least one interface. This allows for rapid, advantageous waking up, for example, from a standby state. If necessary, information can also be exchanged. This may be, for example, information regarding the sensor of the drive shaft of an engine.

[0017] Advantageously, the reduced frequency of the processor clock rate is predefined to maintain bus communication of the link with a control module. Thus, this enables communication with the vehicle control.

[0018] Advantageously, the drive control is designed so that when operating at a reduced processor clock frequency there is no control of the motors and / or no calculation of the mechanical and / or thermal protection functions of the motors, which considerably reduces energy consumption.

[0019] Advantageously, the drive control is designed such that when operating at the reduced frequency of the processor clock, at least one rotor position sensor of a drive motor of a wiper arm is switched off, which makes it possible to further optimize the energy consumption.

[0020] Advantageously, the drive control is designed so that at least in operation with a reduced processor clock frequency, at least one wiper arm position of at least one wiper arm can be detected by at least one output shaft sensor of a drive motor. This makes it possible, in particular, despite the rotor position sensor being switched off, to detect the displaced position of the wiper arm, for example, caused by a high-speed wind, for example, over a prolonged period or due to gusts of wind. This makes it possible, if necessary, to wake up from the standby state, i.e. to have operation at a reduced processor clock frequency and to actuate the wiper arm or wiper arms to return them to their predefined rest position.

[0021] Advantageously, the drive control is designed to increase the clock frequency of the processor from the reduced frequency if, in particular, a control module requests the activation of a drive motor. The control module can, in particular, activate, for example, the cleaning of the window by the operation of the wiper arms requested by the driver or depending on the rain sensor signal of the vehicle to activate the wiper.

[0022] Advantageously, the drive control is designed to activate at least one rotor position sensor if this operation of a drive motor is requested, in particular by the control module. This allows precise input of the position of the wiper arm(s). Brief description of the drawings

[0023] The present invention will be described below in more detail with the aid of an example of an electric motor drive control shown in the accompanying drawings in which:

[0024] [Fig-1] diagram of a vehicle wiper control system according to a example of realization,

[0025] [Fig.2] Perspective view of an electric motor of the control system of the [Fig.l].

[0026] DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0027] [Fig.l] shows a windshield wiper control system of a motor vehicle 105. The control system 100 comprises a control module 110, a first drive control 115 and a second drive control 120. The first drive control 115 comprises a first drive 125 and the second drive control 120 comprises a second drive 130. The drives 125, 130 comprise at least drive motors 125', 130'. The first drive 125 actuates a first wiper arm 135 and the second drive 130 actuates a second wiper arm 140. The first drive control 115 comprises a first interface 145 and a second interface 150. The second drive control 120 comprises a first interface 155 and a second interface 160. A first link 165 connects the control module 110 to the first interface 145 of the first drive control 115.A second link 170 connects the second interface 150 of the first drive control 115 to the second interface 160 of the second drive control 120.

[0028] The control module 110 is part of the vehicle electrical system 105 and communicates at regular intervals with the first drive control 115. Thus, there is an exchange of information, independently of the operating state of the first drive 125 and the second drive 130. The exchanged information includes configuration, status and operating parameters. The first connection 165 may be part of a LIN bus. From the control module 110, the information transmitted via the first interface 145, for example, control information, is detected; it must configure the first drive control 115 which functions as master.

[0029] The first drive control 115 thus controls the drive 125 associated with it according to the information it has received from the first interface 145 and sends corresponding information via its second interface 150 and the second connection 170 to the second interface 160 of the second drive controller 120. The second drive controller 120, whose first interface 155 is not connected to any communication partner, detects the absence of information concerning its first interface 155 so that the latter will be configured as a slave. Then, it uses the information received via its second interface 160 and controls the drive 130 associated with it according to the received information. The second connection 170 is, for example, a Carline connection.

[0030] The drives 125 and 130 are for the DC motors which actuate the wiper arms 135, 140 by a transmission. The drives or transmissions are equipped with sensors not shown for determining the actual movement or absolute position of the wiper arms 135, 140.The drive controllers 115, 120 are connected to these sensors and control the drives 125, 130 depending on the sensors and the information received via the interfaces 145, 160. For the selection of the direction of rotation of the drives 125, 130, the drive controllers 115, 120 have H-bridges (not shown). The drive controllers 115, 120 can be integrated into drives 125, 130.

[0031] The drive controllers 115, 120 serve the electric motors 125', 130' of the drives 125, 130. The drive controllers 115, 120 can be integrated into the drives 125, 130. The drives 125, 130 can also be implemented at least essentially by the drive motors 125', 130'. The drive controllers 115, 120 are designed to operate at a reduced processor clock frequency. Thus, this reduced processor clock frequency is predefined to enable communication via the interfaces 145, 150, 155, 160. In particular, bus communication via the bus connection 165 with the control module 110 remains maintained.

[0032] In operation, at the reduced processor clock frequency, however, there is no control of the motors 125', 130'. In addition, there is no calculation of the mechanical and thermal protection functions of the motors 125', 130'. We are thus in a waiting state with a significant reduction in energy consumption.

[0033] [Fig. 2] shows an electric drive 125 with a motor 125' for the control system shown in [Fig. 1] and corresponding to a possible embodiment for the description. As an example, the drive 125 is shown. The drive 130 can be implemented in a corresponding manner.

[0034] According to a preferred embodiment, it is advantageous that in operation at the reduced processor rate frequency, the rotor position sensor (also called rotary encoder) 180 of a motor 125', 130' of at least one windshield wiper arm 135, 140 is switched off. This results in additional energy savings. When operating at the reduced processor clock frequency, the positions of the wiper arms 135, 140 can still be captured by the output shaft sensors 190 of the respective drive motor 125', 130' as shown by way of example in [Fig. 2] using the output shaft sensor 90 of the motor 125'.

[0035] If, in addition, the actuation of the wiper arms 135, 140 is requested, the frequency of the processor clock rate of the drive controls 115, 120 is increased from the reduced frequency of the processor clock rate. This request may come in particular from the control module 110. At this time, the rotor position sensor 180 is also activated.

[0036] The above description relates to a method for controlling at least one electric drive motor 125', 130' of a motor vehicle, in particular a motor 125', 130' driving windshield wiper arms 135, 140. Operation of the drive controls 115, 120 at a frequency reduced from the processor rate is thus possible.

[0037] NOMENCLATURE OF MAIN ELEMENTS

[0038] 100 Control system

[0039] 105 Vehicle

[0040] 110 Control Module

[0041] 115 First drive command

[0042] 120 Second drive command

[0043] 125 First training

[0044] 125' Drive Motor

[0045] 130 Second training

[0046] 130'Drive motor

[0047] 135 First wiper arm

[0048] 140 Second wiper arm

[0049] 145 First interface of the first drive control

[0050] 150 Second interface of the first drive control

[0051] 155 First interface of the second drive control

[0052] 160 Second interface of the second drive control

[0053] 165 First link of the control module

[0054] 170 Second link of the control module

[0055] 180 Rotor position sensor

[0056] 190 Engine output shaft sensor

Claims

Claims

1. Drive control (115, 120) for electric motors (125', 130') of a motor vehicle, in particular for motors (125', 130') of windshield wiper arms (135, 140), designed for operation at a reduced processor clock frequency, control (115, 120) characterized in that it is designed so that at least in operation at a reduced processor clock frequency, at least one wiper arm position of at least one wiper arm (135, 140) is captured by means of at least one output shaft sensor (190) of a motor drive (125', 130').

2. Drive control (115, 20) according to claim 1, characterized in that the reduced processor clock frequency is predefined to maintain communication via at least one interface (145, 150, 155, 160).

3. Drive control (115, 20) according to claim 1 or 2, characterized in that the reduced processor clock frequency is predefined to enable bus communication via a bus link (165) with a control module (110).

4. Drive control (115, 20) according to one of claims 1 to 3, characterized in that the drive control (115, 120) is designed so that in operation at the reduced processor clock frequency, there is no control of the motors (125', 130') and / or calculation of the mechanical and / or thermal protection functions of the motors (125', 130').

5. Drive control (115, 20) according to one of claims 1 to 4, characterized in that the drive control (115, 120) is designed such that in operation at reduced processor clock frequency, at least one rotor position sensor (180) of a motor (125', 130') is switched off for at least one wiper arm (135, 140).

6. Drive control (115, 120) according to one of the claims 1 to 5, characterized in that it is designed to increase the processor clock frequency from the reduced processor clock frequency if the operation of a motor (125', 130') is requested in particular by a control module (110).

7. Drive control (115, 120) according to claim 6, characterized in that it is designed to activate at least one rotor position sensor (180) if operation of a motor (125', 130') is requested in particular by a control module (110).

8. Control system (100) for at least one electric motor (125', 130') in particular for the motor (125', 130') of at least one windscreen wiper arm (135, 140) with at least one drive control (115, 120) for at least one motor (125', 130'), characterized in that the drive control (115, 120) is implemented according to claims 1 to 8.

9. Method for controlling at least one electric motor (125', 130') of a motor vehicle, in particular at least one motor drive (125', 130') of a windscreen wiper arm (135, 140), method characterized in that it allows the operation of at least one drive control (115), 120) of at least one electric motor drive (125', 130') at a reduced processor clock frequency.

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