EP1230659B1 - Digital rotary switch - Google Patents

Abstract

The invention relates to a device for actuating mobile surfaces on motor vehicles, by means of servo-drives. To predetermine the position of the mobile surface, said device is provided with a desired-value generator (12) and evaluation electronics (1) for evaluating the signals (13) of the desired-value generator (12), said generator and evaluation electronics being interconnected via an interface (10, 11). The desired-value generator (12) is configured as a digital switch, which supplies, in each detent position (15, 16), a digital bit pattern (14) corresponding to the detent position (16).

Description

Technical area

Externally operated window surfaces such as side windows, sunroofs and the like on motor vehicles are increasingly being moved by electrically actuable servomotors today. As a setpoint generator for a downstream evaluation electronics used in previous embodiments analog rotary switch. These are usually designed as a potentiometer having a plurality of finely divided detent positions. Each of these locking positions is assigned to a parking position of the window area to be actuated.

State of the art

The externally operable windows are associated with the passenger compartment of a motor vehicle and are therefore in relation to the passenger compartment in the outer region, so that they are exposed to climatic influences such as ambient humidity or rainwater penetrated to a greater extent. As a potentiometer in roof areas, for example, embedded analog rotary switches are in addition to the sensitivity to moisture also critical in terms of electromagnetic compatibility.

Furthermore, the location of an analog rotary switch is not without influence on the operation of the same. The cable length affects the adjusting in the lines resistance not insignificant, so that depending on the installation of the analog rotary switch, an amplifier must be maintained in addition. The installation of a reinforcing element represents additional installation effort and expense in terms of storage of an additional component during assembly.

In analog rotary switches flow in the lines low currents, which is critical in terms of contact resistance to downstream components. In the worst case, none or a usable signal pulse which can be filtered out of an overlay spectrum is pending at the transition points. Since signal processing is usually done digitally today, an A / D converter is usually connected behind an analogue rotary switch in turn represents an additional component to make the signals of an analog rotary switch of digital processing accessible.

All in all, if an analogue rotary switch is unsuitable for operating a surface which can be actuated externally via an actuator, it nevertheless has a number of disadvantages which do not ensure friction-free operation under all operating conditions.
The document DE 2 848 824 discloses a device according to the preamble of Anspuchs. 1

Presentation of the invention

Digital rotary switches provide independent signals from the place of installation, so that the cabling is to be classified as non-critical with regard to the transition states that are relevant for analog rotary switch arrangements. The electromagnetic compatibility of digital switches is not to be classified as a critical parameter due to the significantly lower voltage level at these components. In previous analog rotary switch configurations to be provided A / D converter can also be saved, as in longer cable strands amplifier arrangements to be provided in order to amplify the signals so that there are further processed signals in the transmitter. This ensures that the output pulses of a digital rotary switch are not lost in the noise floor of the system and there is no need to filter the digital signals to be processed from the noise floor.

Depending on the desired resolution by the fine gradation of the digital rotary switch, the locking positions can be determined by the number of switches; Each of the switch-slider track combinations on the digital rotary switch provides a digital bit pattern in each detent position, for example in the form of a Gray code, so that the evaluation of the detent positions can be carried out in a downstream transmitter without the interposition of an A / D converter. With a plurality of latching positions to be realized on the window surface which can be actuated by means of an actuator, an acceleration of the signal evaluation can be achieved in that a serial interface is provided.

By providing fewer detent positions than individual bits can be assigned, the excess bits can now be used to check the setpoint generator for malfunction. When using a digital rotary switch, in which a plurality of different detent positions can be generated, can be changed from detent position to detent position only one bit in an advantageous manner. As a result, it can be achieved that the moving window surface can be assigned to only one of the two adjacent detent positions and not a completely different detent position. This design option for digital rotary switches makes much simpler and faster signal processing possible. In addition, if fewer detent positions are assigned as bit patterns, the excess bit pattern can be used for error checking of the setpoint generator or the entire actuating system for the externally actuable surface.

When using a digital setpoint generator in the context of an actuator unit for a power-operated surface on motor vehicles, the necessary for the transmission of the signals line between the transmitter and the digital setpoint generator can be significantly reduced by a serial interface. This offers higher degrees of freedom in terms of positioning and less effort in wiring the passenger compartment on a motor vehicle.

drawing

With reference to the drawing, the invention will be described below in more detail.

Figur 1

die Konfiguration eines digitalen Drehschalters bestehend aus Sollwertgeber und Auswerteelektronik,

Figur 2

die Auswertung von 2⁴ Raststellungen von vier verschiedenen Schaltern gemäß des Gray-Codes und

Figur 3

die in analoger Form erfolgende Auswertung digital anstehender Signale des digitalen Sollwertgebers

It shows:

FIG. 1

the configuration of a digital rotary switch consisting of setpoint generator and evaluation electronics,

FIG. 2

the evaluation of 2 ⁴ detent positions of four different switches according to the Gray code and

FIG. 3

the evaluation of digitally occurring signals of the digital setpoint generator taking place in analogous form

variants

From the illustration according to FIG. 1 the configuration of a digital rotary switch consisting of a digital setpoint generator and downstream evaluation electronics is shown in more detail.

The digital rotary switch consists essentially of a digital setpoint generator 12 and a downstream evaluation this 1, which are connected to one another at an interface 10, 11. In the digitally operating setpoint generator 12, a number of switches are provided, which are each connected via a signal line with a plug 11, which acts as an interface 10. Im in FIG. 1 shown setpoint generator 12, for example, four switches 13.1, 13.2, 13.3 and 13.4 are provided, which are connected via a respective separate signal line 13 to a terminal of the plug 11.

The setpoint generator 12 in the form of a digital rotary switch comprises a plurality of switch-slider tracks, which provide a digital bit pattern at each detent position (see FIG. FIG. 2 ). The number of locking positions which can be represented by the n-slider tracks is determined by the number n of switches. With, for example, four switches within setpoint generator 12, 2x2x2x2 = 16 different locking positions can be represented. If only a maximum of 15 detent positions are used in a digital setpoint generator 12 provided with four switches 13.1, 13.2, 13.3, 13.4, the remaining free bit can be used to diagnose the state of the setpoint adjuster connection yes / no.

In an advantageous embodiment of the digital rotary switch, the output lines 13 of the four switches used 13.1, 13.2, 13.3, 13.4 placed on the setpoint generator 12 to the inputs of an interface 10,11, which may be designed as a serial interface in an advantageous manner. From this designed as a serial interface connector 10, 11 branch the inputs in a digital evaluation 1, in the various resistors 3, 4, 5 and 6 of the continued via the interface 10, 11 Signal lines 13 of the digital setpoint generator 12 branch off. Reference symbol 7 denotes the output-side voltage level of the evaluation electronics 1, which corresponds to an open position of one of the switches 13.1, 13.2, 13.3 or 13.4. The incoming into the transmitter 1 signal lines 13, starting from the connector connection 10, 11 extend to the micro-controller whose supply lines are designated by reference numeral 8 within the transmitter 1.

Reference numeral 2, the mass use of the transmitter 1 is characterized, which is also provided on the input side of the Auswerteelektronikbaustein and connected via the plug 10, 11 to the ground line at the setpoint generator 12, so that between the two components 12 and 1 can take place an equipotential bonding.

From the illustration according to FIG. 2 is the evaluation of 2 ⁴ . Detent positions of, for example, four switches using the Gray code out. According to the in FIG. 2 Schemas shown can be with 2 ⁴ switches 13, 16 represent different locking positions, individual individual locking positions corresponding to an individual bit pattern are indicated by reference numeral 16. The total number of possible locking positions is indicated by reference numeral 15 from top to bottom in ascending order. Each individual detent position on the digital setpoint generator 12, identified by reference numeral 16, corresponds to an individual bit pattern 14, which consists for example of the first detent of four digital "0" for all switches 13.1, 13.2, 13.3 and 13.4 of the digital setpoint generator 12. At the in FIG. 2 Gray code shown corresponds to each detent position 16 own bit pattern 14. The use of a Gray code according to FIG. 2 has the advantage that moves from one detent position to the next detent position 16 within the bit pattern 14 in the table FIG. 2 read from top to bottom only changed one bit. This ensures that the position of the setpoint generator 12 between two individual locking positions 16 which is operable with an external drive surface is assigned to the maximum of the adjacent detent position. This avoids the assignment of a completely different locking position, which does not correspond to one of the two adjacent locking positions, so that the cycle time can be shortened considerably. With the Gray code, for example, the occupied by reference numeral 16 position 2 can be either only the Detent position 1 or the detent position 3 and, for example, not a far away detent position 13 or 14 assign, which is further down in the tabular representation according to FIG. 2 are located.

With the proposed solution according to the invention, additional switching signals, for example, additional buttons in the digitally operating setpoint generator 12 can be integrated. If fewer locking positions are required than bits are available, the remaining bit of the digitally operating setpoint generator 12 can be checked for malfunction. Thus, for example, it can be easily determined whether the setpoint generator 12 is connected with a maximum of 15 locking positions or not, if the diagnosis of the remaining free bit (all switches open) of the setpoint generator 12 can be done.

At the in FIG. 1 shown digital rotary switch consisting of digital setpoint generator 12 and digitally operating transmitter 1 can be detected whether the respective switches 13.1, 13.2, 13.3 and 13.4 are closed or open. An open according to this configuration switch 13.1, 13.2, 13.3 or 13.4 corresponds to the same potential as a non-connected setpoint generator. In digital processing of the output side of the digital setpoint generator 12 pending pulses corresponds to the switching state "open" the voltage state 12 and thus a logical "1" according to the provided in the transmitter 1 switching level. In the closed state of a respective switch 13.1, 13.2, 13.3 and 13.4, a voltage level of 0 volts is detected, which is equated to a logical "0".

An "open" switch 13.1, 13.2, 13.3 and 13.4 thus corresponds to the same potential as a non-connected setpoint generator 12th

From the illustration according to FIG. 3 shows an alternative embodiment of the solution proposed according to the invention, in which an analogous form of evaluation of digitally pending signals is shown.

In the digital further processing of digital information, which comes from the digitally operating setpoint generator 12, can only be detected whether the respective Switch 13.1, 13.2, 13.3 or 13.4 is closed or not. In one as shown in FIG FIG. 3 proposed analog readout of the information of the digital setpoint generator 12 can also be distinguished whether the setpoint generator 12 is connected or whether each individual connection line 13 is interrupted between the setpoint generator 12 and the transmitter 1 via the interface 10 or not. For this purpose, according to this embodiment, different switching level states are defined. In this embodiment, an open switch 13.1, 13.2, 13.3 or 13.4 corresponds to the concern of a voltage level of 2.5 volts, while a closed position of each switch 13.1, 13.2, 13.3 or 13.4 is defined by the voltage level 0 volts. A broken line 13 is detected by the presence of the voltage level of 12 volts which corresponds to the motor vehicle supply voltage. Unlike the in FIG. 1 shown configuration of the digital setpoint generator 12 are in the in FIG. 3 setpoint generator configuration shown the respective switches 13.1, 13.2, 13.3 and 13.4 individual shunt resistors 17 connected in parallel. The resistors 17.1, 17.2, 17.3 and 17.4 are parallel to the respective switches 13.1, 13.2, 13.3 and 13.4, wherein with reference numeral 18 of the equipotential bonding via the serial interface 10 between the two components digital setpoint generator 12 and transmitter 1 is made.

For the transmission of the signals to be transmitted between the two building components 12 and 1, the signal lines 13 from the digital setpoint generator 12 to the corresponding inputs 9 on the transmitter 1 via the plug terminals 19, i. the plugs 19.1, 19.2, 19.3 and 19.4 for the respective lines of the individual switches 13.1, 13.2, 13.3 and 13.4 connected to each other. The at a high resolution detent, i. Many adjustable or representable locking positions required line overhead can be drastically reduced by the configuration of the interface 10, 11 as a serial-acting interface. The digital bit code of each bit pattern 12 can be transmitted via a serial interface much easier, faster and with less wiring effort between the components 12 and 1.

With the proposed solution according to the invention can be used in applications in motor vehicles analog rotary switch replaced by digital rotary switch with associated with the advantage that their wiring is much easier. A reduction of the wiring effort is highly desirable in the assembly of, for example, the headliner in the passenger compartments of motor vehicles, since the laying of line trees or of the wiring in the motor vehicle today during final assembly mostly still done manually. Furthermore, with the use of digital rotary switches, the cable length is of minor importance in terms of the forming and increasing with the cable length line resistance. The critical transmission point of the contact resistances between the rotary switches and the downstream components can occur when using a digital rotary switch in the background. Furthermore, a conversion of analog signals recorded by means of a potentiometer via the interposition of an A / D converter in the embodiment proposed according to the invention is no longer necessary. Furthermore, in the resolution of a rotary switch in individual detent stages no restriction with respect to the resolution by the self-adjusting output signals to a potentiometer. Rather, only the number of switches to be used 13.1, 13.2, 13.3 and 13.4 within a digitally operating setpoint generator is decisive for the resolution with regard to the number of locking positions to be set 15. When using five binary switching elements 13.1, 13.2, 13.3 and 13.4 can be 2 ⁵ , ie realize 32 locking positions, which is considered sufficient for both the resolution of the sliding position of a sliding roof, as well as provides enough capacity to check by means of the unnecessary bits in the bit pattern 14, the digitally operating setpoint generator 12 with regard to the presence of malfunction.

LIST OF REFERENCE NUMBERS

1

evaluation

2

earth terminal

3

Resistor R ₁

4

Resistor R ₂

5

Resistor R ₃

6

Resistance R ₄

7

Voltage level 12 volts

8th

Micro-controller

9

Inputs evaluation electronics

10

interface

11

plug

12

Setpoint generator

13

signal lines

13.1

Switch 1

13.2

Switch 2

13.3

Switch 3

13.4

Switch 4

14

bit pattern

15

detent position

16

individual rest position

17

parallel resistance

17.1

Resistor R ₅

17.2

Resistor R ₆

17.3

Resistor R ₇

17.4

Resistor R ₈

18

earth terminal

19

connector terminals

19.1

management

19.2

Line 2

19.3

Line 3

19.4

Line 4

Claims (10)

1. Device for activating surfaces on motor vehicles which are moved by means of actuator drives, wherein, in order to predefine the position of the movable surface, a set point value signal transmitter (12) is provided, characterized in that, in order to evaluate the set point value signal transmitter signals (13), an electronic evaluation system (1) is provided which are connected to one another via an interface (10, 11), wherein the set point value signal transmitter (12) is constructed as a digital switch which supplies a digital bit pattern (14) in each latched position (15, 16).
2. Device according to Claim 1, characterized in that the set point value signal transmitter (12) contains a plurality of switch slider paths (17; 17.1, 17.2, 17.3 and 17.4) which, in each latched position (15, 16), supply a digital bit pattern (14) corresponding to this latched position (16).
3. Device according to Claim 2, characterized in that the number of 2ⁿ latched positions (15) which can be represented is determined by the number n of the switches (17).
4. Device according to Claim 1, characterized in that, when there are fewer than 2ⁿ latched positions (15) to be represented, the set point value signal transmitter (12) is functionally checked with the remaining bit pattern (14).
5. Device according to Claim 1, characterized in that, when the signals (13) of the set point value signal transmitter (12) are evaluated in a digital fashion, the supply voltage level corresponds to the open position of a switch (17).
6. Device according to Claim 5, characterized in that, when the signals (13) of the set point value signal transmitter (12) are evaluated in a digital fashion, the closed position of a switch (17) corresponds to the voltage level of 0 volts.
7. Device according to Claim 1, characterized in that the interface (10, 11) between the digital set point value signal transmitter (12) and the electronic evaluation system (1) is constructed as a serial interface.
8. Device according to Claim 1, characterized in that, when the signals (13) of the set point value signal transmitter (12) are evaluated in an analogue fashion, the open position of a switch (17) is defined by a voltage level below the supply voltage.
9. Device according to Claim 1, characterized in that, when the signals (13) are evaluated in an analogue fashion, a break in a signal line (13) is detected by detecting the supply voltage.
10. Device according to Claim 1, characterized in that the bit patterns (14) are present in the form of Gray codes in which a bit is changed when the latched position (15, 16) changes.

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