Electricity: motive power systems – Positional servo systems – Digital or numerical systems
Reexamination Certificate
1999-07-28
2001-08-28
Masih, Karen (Department: 2837)
Electricity: motive power systems
Positional servo systems
Digital or numerical systems
C318S569000, C318S443000, C318S560000, C318S603000, C318S572000
Reexamination Certificate
active
06281653
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a method of detecting after-running of electrical servomotors, especially electrical servomotors in motor vehicles, with incremental position detection.
2. Prior Art
Methods for detecting after-running of electrical servomotors are known in which evaluation electronics are used to detect position signals of the position indicators and store the states of the incremental position indicators in nonvolatile memory.
A process for position detection of a motor vehicle part driven in two directions by electric motors is known from EP 0 603 506 A2. With the aid of a counter, when the part moves in its two directions, counting pulses of a position indicator are input into the counter in order to reduce or increase the count in accordance with the predetermined movement. After the drive motor is switched off, the pulses supplied from the position indicator are analyzed in their chronological distance from the shutoff time and are associated with a further movement of the counter if the chronological distance of the pulses does not exceed a predetermined measure. When the drive motor is subjected to a polarity reversal the counting direction is associated with the new movement direction only when the distance of the pulses reduces further after the polarity reversal.
In this known process, nothing is disclosed regarding measures that permit a tracking or after-running detection with prior disconnection from the supply voltage and a storage of position data for the subsequent position correction with reconnection to the supply voltage as well as a reduction in the time required for the after-running detection.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved method of detecting after-running of electrical servomotors with incremental position detection, which avoids the disadvantages mentioned above.
This object, and others which will be made more apparent hereinafter, are attained in a method for detecting after-running of electrical servomotors with incremental position detection of the above-described type in which evaluation electronics detect position signals from the position indicators and store the states of the incremental position indicators, which are detected in conjunction with the position signals, in a non-volatile memory.
The method according to the invention comprises intermittently disconnecting the evaluation electronics with a supply voltage to intermittently switch the evaluation electronics off and correcting the status of the incremental position indicators according to a comparison of the stored states of the incremental position indicators with the states of the incremental position indicators after the evaluation electronics are switched on again after being switched off.
The after-running detection according to the invention has the advantage over the prior art that all important data regarding the system status are stored in a nonvolatile memory and can consequently be used as a basis with the next system startup.
According to the invention, in the tracking detection of electrical servomotors with incremental position detection, evaluation electronics are provided in principle for the tracking detection, which electronics detect the position signals of position indicators and wherein the evaluation electronics store the detected states of the position signals and the states of the position indicators in a nonvolatile memory.
Advantageous improvements and updates of the tracking detection of electric servomotors according to the invention, as described above are possible by means of the measures given in the remaining claims.
According to a particularly advantageous embodiment of the device according to the invention, the evaluation electronics can be intermittently disconnected from the supply voltage and are provided with a buffer, which is large enough for the position detection and storage after the evaluation electronics are disconnected from the supply voltage. By means of this particular embodiment, the evaluation electronics are switched on in an energy-saving manner only if they need to be used. Since all important system data have been stored before or around the time of the shutoff, they are available again after the new system startup and form the basis for the continued functioning.
According to a particularly advantageous embodiment of the invention, the storage can already be carried out at a time at which the last possible position signal has not yet been input.
In a further suitable embodiment of the device according to the invention, with the subsequent use of at least two position signals that are offset from each other, i.e. with a reconnection of the evaluation electronics to the supply voltage, a definite rotation direction allocation can be carried out by subsequent correction and allocation of the last edge change of one of the position indicators by means of the evaluation electronics. The last edge change by one of the two position indicators can thus always be definitely allocated.
According to a particularly advantageous additional embodiment of the after-running detection according to the invention, after a reconnection of the evaluation electronics to the supply voltage, if the stored values of the position indicators jointly indicate a state change, the evaluation electronics take the previous rotation direction into consideration in a correction.
The after-running detection according to the invention is used in a particularly advantageous manner in motor vehicles to detect the position when an electric motor, which is used for positioning purposes, is switched off. This can be the case, for example, with window lifters, sunroofs, and seats.
In an additional advantageous embodiment of the invention, Hall sensors that are electrically offset by 90° are provided as position indicators.
According to a particularly suitable embodiment of the after-running detection according to the invention, the evaluation electronics include a micro-controller.
According to another advantageous improvement of the invention, an electronically programmable memory is used as the nonvolatile memory. According to a suitable embodiment, an EEPROM is used as the nonvolatile memory, which is preferably a component of the micro-controller.
REFERENCES:
patent: 5130710 (1992-07-01), Salazar
patent: 5763874 (1998-06-01), Luciano et al.
patent: 5956659 (1999-09-01), Spies et al.
patent: 6111384 (2000-08-01), Stagnitto
patent: 6121745 (2000-09-01), Komm
patent: 196 06 471 A1 (1996-09-01), None
patent: 0 365 736 B1 (1994-05-01), None
patent: 0 615 111 A1 (1994-09-01), None
Article “Busfaehinger Intelligenter Sensor Fuer Winkel Und Wege” By W. Kuntz and H. Walcher, In Technisches Messen Tm. 53 Jahrgang. Heft 6 1986.
Heib Johannes
Kahles Patric
Masih Karen
Robert & Bosch GmbH
Striker Michael J.
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