Arrangement with an electric motor
Assigneeebm-papst St. Georgen GmbH & Co. KG
InventorsJorg Hornberger, Frank Jeske, Hansjorg Kaltenbrunner, Arno Karwath, Hermann Rappenecker, Thomas Dufner
Life of this patent
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Abstract
The rotation speed of an electric motor (9) is controlled by a controller (6) which receives its setpoint from a characteristic function (23). The characteristic function (23) calculates a setpoint for the controller (6) on the basis of an originally analog variable A (2) that is converted to digital by an A/D converter AD (10), with the aid of support values of a “MEM+DATA” characteristic that are stored in a memory (4); those values not predefined by the support values are calculated by interpolation.
Claims68
An electric motor (9) having a rotation speed controlled by a changeable physical variable (2), in particular a temperature;
- having a characteristic field, stored in the form of individual digital values, for the allocation of values of said physical variable to corresponding rotation speed values of the electric motor;
- and
- having a microcontroller (11) or microprocessor which has access to the stored individual digital values:
The electric motor (9) as defined in one or more of the foregoing claims, having an A/D converter (10) for converting an analog physical variable (2) into a digital value.
The electric motor as defined in one or more of the foregoing claims, in which the A/D converter has downstream from it a hysteresis function (S504) which, in the event of small changes in the physical variable, retains the digital value ascertained during a previous A/D conversion in order to reduce rotation speed fluctuations of the motor.
The electric motor (9) as defined in one or more of the foregoing claims, in which the A/D converter (10) has downstream from it a plausibility function (S506) which checks the digital value ascertained during an A/D conversion for plausibility, and replaces an implausible digital value with a predefined digital value.
The electric motor (9) as defined in one or more of the foregoing claims, in which a rotation speed controller (6) is associated with the electric motor, and the signal generated during the A/D conversion is used to generate a setpoint signal for that rotation speed controller.
The electric motor (9) as defined in one or more of the foregoing claims, in which a nonvolatile memory (26) is provided for storing the digital values of the characteristic field.
The electric motor (9) as defined in one of the foregoing claims, in which the operating time is counted.
The electric motor (9) as defined in claim 22, in which the operating time can be interrogated from outside.
A method for controlling a physical variable, in particular a rotation speed, having the following steps:
- a) in order to ascertain the system deviation, a difference is determined between a desired value for the physical variable (in digital form), and an actual value for the physical variable (also in digital form);
- b) the sign and absolute value of that difference are ascertained;
- c) an analog memory element is charged or discharged, depending on the sign;
- d) the duration of the charging or discharging operation is in each case substantially proportional to the magnitude of the ascertained absolute value of the difference;
- e) a value dependent on the charge of the analog memory element is used to influence the pulse duty factor of an actuating member that in turn influences, with its output signal, the physical variable that is to be controlled (FIG. 20).
A method for temperature-dependent control of the rotation speed of an electric motor having the following steps:
- a) value clusters of characteristic definition points are stored in a memory, said value clusters containing at least one value characterizing a specific temperature, and one rotation speed datum associated with that temperature;
- b) a present value characterizing the temperature that controls the motor rotation speed is sensed at time intervals;
- c) that sensed value is compared to the stored values that characterize the temperature and are contained in the stored value clusters;
- d) a stored value adjacent to the present value is ascertained;
- e) by way of an interpolation proceeding from that adjacent value, a rotation speed datum for the sensed present value is ascertained;
- f) a value (H_L) derived from that interpolated rotation speed datum is conveyed to a rotation speed controller of the electric motor to define a rotation speed setpoint.
A method for A/D conversion in an arrangement having a voltage divider containing a temperature-dependent resistor, one tapping point of that voltage divider defining the potential at the one input of a comparator, and the potential at the other input of the comparator being determined by a capacitor that can be charged via a constant-current source, having the following steps:
- a) first the capacitor is discharged;
- b) then a measurement is made of the time required for the capacitor, as it is charged by the constant-current source, to reach the potential of the other input;
- c) that time is used as an indication of the temperature of the temperature-dependent resistor (FIG. 7).
An electric motor (9) having discrete values stored in a memory which, in the form of support values, define a temperature/rotation speed characteristic, the discrete values being modifiable via a data connection to an input device arranged outside the electric motor.
A method for operating an electronically commutated motor having associated with it a microprocessor or microcontroller and a program associated therewith, that program serving to control a plurality of motor functions of different priorities, having the following steps:
- a) a plurality of requestable routines necessary for operation of the motor are provided;
- b) when a requestable routine is needed, a corresponding request signal for it is set;
- c) a higher-level program function is used to check which requested routine has the highest priority, and that highest-priority routine is executed first;
- d) following execution of that highest-priority routine, the request signal associated with that routine is reset (FIG. 26).
A motor (9) having a microprocessor or microcontroller (11) and a bus, in which the microprocessor or microcontroller (11) controls both the bus and the motor.
Dependencies are inferred from the claim text.