GB2341696A

GB2341696A - Apparatus for automatically activating a device in a motor vehicle

Info

Publication number: GB2341696A
Application number: GB9920757A
Authority: GB
Inventors: Norbert Hog; Andreas Gille; Bruno Hodapp; Gebhard Michenfelder; Rainer Pientka; Hans Meier; Henry Blitzke; Manfred Burkart
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1998-09-15
Filing date: 1999-09-03
Publication date: 2000-03-22
Anticipated expiration: 2019-09-03
Also published as: DE19842064A1; ITMI991879A0; FR2783224A1; IT1313348B1; GB2341696B; GB9920757D0; ITMI991879A1; FR2783224B1

Abstract

An apparatus 10 for automatically activating a device 20 in a motor vehicle in dependence upon wetting of the vehicle windscreen 15 is of a modular design so that individual modules A, B, C can be disposed spatially separate. The modules are divided into function blocks, namely a sensor module A, an evaluation module B and an activation module C. The sensor module A is fastenable to the windscreen 15 and produces a sensor signal in dependence on wetting of the windscreen. The evaluation module B produces a control signal in response to the sensor signal, and the activation module C supplies an actuating signal for activating the device 20. In particular, the device 20 can be a wiper motor of a windscreen wiping system 25, but the system could also activate devices such as a windscreen heater or headlamp wiper in response to the sensor module A. The activation module can be integrated in the central electronics of the vehicle, and the output of the evaluation module can be compatible with the central electronics.

Description

2341696 A Daratus for autornafically activating a device

Background art

The invention proceeds from an apparatus for automatically activating a device, in particular a wiper motor of a motor vehicle windscreen wiping system, in dependence upon a wetting of a windscreen according to the preamble of the main claim. 10 An apparatus for operating a rain detector is already known (DE 41 12 847 AI), which comprises a rain sensor comprising a control arrangement, a transmitter, a receiver and optionally a signal conditioning device and an evaluation device. In said case, the control arrangement controls the transmitter so that the latter produces a signal which is acquired by the receiver. The latter in turn supplies a 15 sensor signal to the signal conditioning device, which passes a conditioned sensor signal to the evaluating device. The evaluating device determines an actuating signal for switching on a windscreen wiping system in dependence upon the sensor signal as well as in dependence upon a preselectable threshold. 20 Said apparatus has the drawback that it is not of a modular design and so individual function blocks are not easily exchangeable and that the latter are generally not compatible. A further drawback is that it is difficult from an aesthetic and practical viewpoint 25 to provide a flexible arrangement of the apparatus, e.g. in a motor vehicle, because the rain sensor usually has a specific minimum size on account of the integrated electronics and evaluation circuit.

2 Advantages of the invention The apparatus according to the invention having the characteri=g features of the main claim has the advantage that a modular design of the apparatus is provided, with the result that the individual modules may be arranged spatially separate without difficulty. The apparatus is divided into modules which here comprise, for example, function blocks in a sensor module, an evaluation module and an 10 activation module. A further advantage is that the sensor module detects the wetting of a windscreen yet requires a minimum of electronic components and may therefore be of a small and unobtrusive design. A small sensor module on the front windscreen of the 15 motor vehicle obstructs the view of the driver very little or not at all. A fin-ther advantage is that the output signal of the sensor module is supplied to the spatially remote evaluation module. The evaluation module is advantageously disposed so as to be invisible to the diriver, e.g. above the sun visor mi the motor 20 vehicle interior. The evaluation module produces an output signal, from which the downstream unit (activation module) may derive the activation of the wiper motor. The output of the evaluation module is preferably to be connected compatibly with central 25 electronics of the motor vehicle.

It is likewise advantageous that the activation module, depending on the requirements in the motor vehicle, is an integral part of the central electronics of 3 the motor vehicle, integrated on the wiper motor or disposed m a separate socalled relay box in the motor vehicle.

Advantageous developments and improvements of the features indicated in the main claim arise by virtue of the measures outlined in the sub-claims. Of particular advantage is the compatibility of the connections between the modules, which allow a flexible arrangement of the modules in the motor vehicle and a wide range of possible combinations.

Drawings Embodiments of the invention are illustrated in the drawings and described in detail below. The drawings show:

Figure 1 a block diagram of the modules according to a first embodiment and Figure 2 a diagrammatic view of the sensor module according to a flirther embodiment.

Description of the embodiments

The apparatus 10 for automatically activating a windscreen wiping device according to Figure 1 comprises three modules A, B,C, which are divided into function blocks and may be arranged spatially separate in the motor vehicle. The modules A, B, C are compatibly connected to one another by lines 1, 2. 25 The apparatus 10 activates a wiper motor 20 whick in dependence upon a wetting by moisture or dirt accumulation of a windscreen 15, in particular a motor vehicle 4 front wi ndscreen, automatically sets a sketched wiper 25 in continuous or intermittent Wiping operation or wipe-wash operation.

For manual control of the apparatus 10 and the wiper motor 20, an operator switch 30 is further provided, which is connected to one of the modules A, B, C, preferably to module C.

The modules A, B, C are divided into the following function blocks:

Ile first module A, hereinafter referred to as the sensor module, is disposed on the windscreen 15, the wetting of which is to be detected. The sensor module A substantially comprises the optical elements which are used for an optoelectronic ram sensor. Said elements are specifically a beam transmitter 17 and a beam receiver 19, as well as means of injecting the transmitter beam 50 into the 15 windscreen 15 and means of extracting the beam from the windscreen 15. The transmitter beam 50 is in said case, according to the principle of total internal reflection, reflected at the wettable outside in the windscreen 15 and transmitted one or more times. A measuring distance of the ram sensor is thereby provided between transmitter 17 and receiver 19 because, upon wetting of the windscreen 20 15, the ratio of the refractive indices varies in such a way that, at said point, the transmitter beam 50 is extracted from the windscreen 15 and cannot therefore be supplied to the receiver 19. Optical components for guiding the beam are moreover likewise disposed inside the sensor module A. 25 Ile only electronic equipment provided is for activating the transmitter 17. Thus, for example, the transmitter 17 is operated in a clocked manner in order, in the interval breaks, to acquire and evaluate the ambient or stray light reaching the receiver 19. In addition, by virtue of a clocked operation of the transmitter the output of the transmitter 17 is reduced and so its service life is extended.

The sensor module A produces, as an output signal, a sensor signal "a" which reproduces the wetting of the windscreen 15 by moisture or rain and which is evaluated in the downstream second module B. The sensor signal "a" is transmitted via the line 1.

The second module B, hereinafter referred to as the evaluation module, evaluates the supplied sensor signal "a" with a view to activation of the windscreen wipers, e.g. in accordance with the patent specification DE-PS 196 21 627 or the not previously published patent application bearing the file number AZ 197 40 364.

Usually, cut-M and cut-out thresholds are stored in the evaluation module B and, when the sensor signal "a" exceeds or falls below said thresholds, a control signal "b" is produced as an output signal of the evaluation module B. For example, the evaluation module B comprises a microcontroller and also an interface, in particular a serial interface, which is connected in a compatible manner by a bidirectional data line 2 to module C.

The evaluation module B is moreover provided so as to be invisible to the driver, e.g. above a sun visor in the motor vehicle interior. Any other point in the motor vehicle is also conceivable because, according to the invention, a spatially separate arrangement of the modules A, B, C is possible.

The module C, hereinafter referred to as the activation module or motor activating device, on the basis of the control signals "b" transmitted via the second line 2 activates the wiper motor 20 by means of actuating signals "c" via relays or 6 transistors. The necessary electronics of the activation module C are in said case integrated either in the vehicle body central electronics or in the wiper motor or are separately disposed.

The connection between the modules A, B, C is effected by means of electric lines 1, 2 which are to be fastened by means of plug-in contacts to the modules A, B, C. An operator switch 3 0 switches on or off the entire apparatus - 10 or merely the 10 automatic windscreen wiping mode by means of the rain sensor Mi that the activation module C, e.g. the central electronics, activates or deactivates the evaluation module B via the bidirectional data line 2. The operator switch 30 is realized by a momentary-contact switch or a steering drop arm. is However, it is moreover also possible for a respective two of the modules A, B, C or the activation module C and the wiper motor 20 to be integrated m a common housing. Besides the activation of a wiper motor 20, the activation of further devices 20 20 such as, for example, a windscreen heater, a headlamp wiper or rear windscreen wiper is equally possible. Furthermore, given an acquisition and evaluation of light from external sources by the rain sensor, an activation of the headlamps and other light sources on the motor vehicle is extremely advantageous. 25 In an alternative embodiment according to Figure 2, the sensor module A as a purely optical module on a windscreen 15 comprises merely optical devices and components for guiding the light beam 50. The transmitter 17 and receiver 19 as well as their wiring are housed in the downstream evaluation module B. 7 The sensor module A is made, for example, of a transparent plastic material having the optical properties required for a rain sensor. The sensor module A is therefore to be disposed in the field of vision of the driver when, because of its geometry, the driver may see through it.

The evaluation module B is situated, for example, in a roof module, mirror base, central electronics or a separate housing.

An optical fibre, for example, may be used as line connection 1 between the modules A and B. The sensor signal 'W' therefore corresponds to the beam 50, which is guided onto the receiver 19 and reproduces the wetting of the windscreen 15.

8

Claims

Claims

Apparatus (10) for automatically activating a device, in particular a wiper motor (20) of a motor vehicle windscreen wiping system, m dependence upon a wetting of a windscreen (15), characterized in that the apparatus (10) comprises the following modules (A, B, C):

- a sensor module (A), which is fastenable to the windscreen (15) and produces a sensor signal (a) in dependence upon the wetting of the windscreen (15), - an evaluation module (B), which evaluates the sensor signal (a) with a view to activation of the device (20) and produces a control signal (b), and - an activation module (C), which in dependence upon the control signal (b) supplies an actuating signal (c) for activating the device (20), and that the modules (A, B, C) are to be disposed as units which are spatially separate from one another in the motor vehicle.
2. Apparatus according to claim 1, characterized in that the sensor module (A) comprises a light-emitting transmitter and a light detecting receiver.
3. Apparatus according to claim 1, characterized in that the evaluation module (B) comprises a microcontroller.
4. Apparatus according to claim 1, characterized in that the activation module (C) is integrated in central electronics of the motor vehicle or on the wiper motor (20) or is separately disposed and in 9 particular comprises a power circuit for operating the wiper motor (20).
5. Apparatus according to one of the preceding claims, characterized in that an output of the evaluation module (B) is compatible with the central electronics of the motor vehicle.
6. Apparatus according to one of the preceding claims, characterized in that the modules (A, B, C) are connectable by lines (1, 2), which are in turn fastenable by means of plug-and-socket connections to the modules (A, B, C).
7. Apparatus according to claim 1, characterized in that the sensor module (A) comprises merely optical components and is connected by an optical fibre as a guide (1) to the evaluation module (B).
8. An apparatus for automatically activating a device, the apparatus being substantially as herein described with reference to the accompanying drawing.