METHOD FOR THE VIBRATION- AND NOISE-REDUCED OPERATION OF AN ELECTRIC-MOTOR DEVICE AND ELECTRIC-MOTOR DEVICE

Abstract

A vibration and noise-reduced electric-motor device for an electrical household appliance or an electrical sliding roof. The invention includes a method for the vibration and noise-reduced operation of an electric-motor device. The electric-motor device has an electric-motor assembly, a main body, and a driven group of accessories. The electric motor assembly includes an electric motor, a control and evaluation unit, a data memory, a current regulator, a rotor angle sensor and a torque evaluator. The electric motor has a stator, a rotor and motor coils. In the method, a setpoint current stored in a value table in the data memory is applied to the motor coils in accordance with the rotor angle. The torque deviation resulting at the setpoint current, between the setpoint torque and the actual torque is determined, and an optimized new setpoint current value is calculated by interpolation and is written into the value table.

Claims

1-6. (canceled)

7. A method for the vibration- and noise-reduced operation of an electric-motor device, comprising: providing the electric motor device including an electric motor assembly, a main body and a driven group of accessories; the electric motor assembly including an electric motor, a control and evaluation unit, a data memory, a current regulator, a rotor angle sensor and a torque evaluator, and the electric motor having a stator, a rotor and motor coils; including the following procedural steps: a) defining a value table in the data memory including several table points, the table points being value tuples, each of the value tuples containing a pair of values from a setpoint torque, a rotor angle. and an assigned setpoint current; b) performing a partial cycle, including the following sub-steps: b1) providing specification of a setpoint torque; b2) detecting a first actual rotor angle with the rotor angle sensor; b3) the control and evaluation unit reading-out the setpoint current which is assigned to a first pair of values from the setpoint torque and the first actual rotor angle by determining two table points closest to a specified setpoint torque and two table points closest to the actual rotor angle and calculating a distance of real values of the setpoint torque and the first actual rotor angle to the two table points, determining a setpoint current by bilinear interpolation from respective setpoint currents of the four table points; b4) setting the setpoint current with the current regulator; b5) applying current to the motor coils; b6) evaluating actual torque with the torque evaluator; b7) comparing the setpoint torque and the actual torque with the control and evaluation unit for determining a torque deviation; b8) calculating a corrected setpoint current with the control and evaluation unit, on the basis of the torque deviation, for all four table points most recently used as a function of interpolation distance used; b9) entering the calculated values of the corrected setpoint current in four relevant value tuples of the value table with the control and evaluation unit and deleting previous values of the setpoint current; c) repeating performance of the partial cycle until a rotor angle corresponding to a complete motor state is reached for forming a complete cycle; d) repeating performance of a complete cycle.

8. The method for the vibration- and noise-reduced operation of an electric-motor device according to claim 7, wherein the value table is configured for a complete rotor rotation.

9. An electric-motor device, comprising: a main body; a driven group of accessories; an electric-motor assembly including an electric motor, a control and evaluation unit, a data memory, a current regulator, a rotor angle sensor and a torque evaluator, said electric motor having a stator, a rotor and motor coils, said electric motor disposed in a positional relationship at the main body and rotationally driving said driven group of accessories; said electric-motor assembly being configured for performing the following steps: a) storing a value table in the data memory, the value table including table points, the table points being value tuples, each of the value tuples containing a pair of values from a setpoint torque and a rotor angle as well as an assigned setpoint current; b) performing a partial cycle, including the following sub-steps: b1) providing specification of a setpoint torque; b2) detecting a first actual rotor angle with the rotor angle sensor; b3) said control and evaluation unit reading-out the setpoint current which is assigned to a first pair of values from the setpoint torque and the first actual rotor angle, determining two table points closest to a specified setpoint torque and two table points closest to the actual rotor angle and calculating a distance of real values of the setpoint torque and the first actual rotor angle to the two table points, determining a setpoint current by bilinear interpolation from respective setpoint currents of the four table points; b4) setting the setpoint current with said current regulator; b5) applying current to said motor coils; b6) evaluating actual torque with said torque evaluator; b7) comparing the setpoint torque and the actual torque with said control and evaluation unit for determining a torque deviation; b8) calculating a corrected setpoint current with said control and evaluation unit, on the basis of the torque deviation, for all four table points most recently used as a function of interpolation distance used; b9) entering the calculated values of the corrected setpoint current in four relevant value tuples of the value table with the control and evaluation unit and deleting previous values of the setpoint current; c) repeating performance of the partial cycle until a rotor angle corresponding to a complete motor state is reached for forming a complete cycle; d) repeating performance of a complete cycle.

10. The electric-motor device according to claim 9, wherein said electric-motor device is constructed a household appliance.

11. The electric-motor device according to claim 10, wherein said driven group of accessories includes a food-crushing mechanism.

12. The electric-motor device according to claim 10, wherein said electric-motor device is constructed as an electric vehicle roof.

Description

[0117] FIG. 1 is a schematic representation of an electric-motor motor device, which in the embodiment example is designed as a household appliance driven by an electric motor. In the exemplary embodiment, it is a multifunctional appliance which is provided with interchangeable driven group of accessories. FIG. 1 shows the main body II, at which the electric motor assembly I and the driven group of accessories III are arranged. The driven group of accessories III comprises a transmission shaft which carries a food-crushing mechanism 10. In the exemplary embodiment, the food-crushing mechanism 10 is a rotating cutting blade.

[0118] FIG. 2 shows a schematic structure of the electric-motor assembly.

[0119] The electric-motor assembly comprises a control and evaluation unit 2, a data memory 3, a current regulator 4, a rotor angle sensor 5, a torque evaluator 6 and an electric motor 1.

[0120] The current regulator 4, the rotor angle sensor 5 and the torque evaluator 6 are each connected to the electric motor 1 and the control and evaluation unit 2.

[0121] In this embodiment, the data memory 3 with the value table is integrated in the control and evaluation unit 2.

[0122] The electric motor 1 comprises a stator 7, a rotor 8 and several motor coils 9.

[0123] The current regulator regulates the setpoint currents for the motor coils to the values transmitted by the control and evaluation unit.

[0124] The rotor angle sensor 5 determines the position of the rotor 8 and transmits it to the control and evaluation unit 2 and to the torque evaluator 6.

[0125] The torque evaluator 6 evaluates the actual torque referred to a specific rotor angle from the parameters applied to the electric motor 1, in the exemplary embodiment in particular from the actual current, and also transmits this value to the control and evaluation unit 2. Based on this value, the control and evaluation unit 2 calculates a torque deviation and, on this basis, optimized setpoint current values and enters them into the value table of the data memory 3 thus replacing the previous setpoint current values.

[0126] FIG. 3 is a schematic representation of the method for the noise-reduced operation of an electric-motor device. The flow chart shows a summary of all the procedural steps from a) to d), wherein the procedural step b) is shown with all its sub-steps. The partial cycle (procedural step b)) is repeated until the end of the first motor state is reached, and upon reaching the first motor state, it is repeated until the end of the next motor state is reached (procedural step c)). This is a complete cycle.

[0127] The complete cycle is repeated for all motor states until a complete 360° rotation of the rotor is achieved (procedural step d)). Once a complete rotation of the rotor has been terminated, the entire sequence can be repeated as often as required to effect a continuous rotation.

[0128] The value table is continuously updated in procedural step b)9.

[0129] FIG. 4 shows a compilation of graphs relating to the torque behaviour of the electric motor, in this embodiment a reluctance motor, during the application of the method. At the beginning (t=0 or on the left), the switched reluctance motor still shows high torque peaks, also known as torque ripples, which are caused by a suboptimal superposition of the partial torques, especially during the transition from one motor state to the next (at the bottom left). After several complete cycles, the torque peaks are significantly reduced (at the bottom right) and the partial torques overlap more advantageously. The torque peaks are responsible for a vibration of the rotor teeth and stator teeth and thus for the loud running noise of the reluctance motor. Hence, the reduction of the torque peaks also reduces the motor noise.

[0130] FIG. 5 shows the interpolation of the values in the coordinate system a) and the calculation of the corrections for the setpoint currents in table b).

[0131] The value interpolation according to procedural step b)3 is represented graphically in the coordinate system a). The control and evaluation unit is given the setpoint torque and the rotor angle sensor provides the actual rotor angle (Θ.sub.ist). The control and evaluation unit determines the four closest table points (P11, P12, P21, P22) and interpolates a setpoint current (I.sub.soll) by bilinear interpolation. The value for a setpoint current (I.sub.soll) obtained in this way by interpolation is set by the current regulator in procedural steps b)4 and b)5 and transmitted to the motor coils.

[0132] In procedural step b)6, the torque evaluator evaluates the actual torque (M.sub.ist) applied and, in procedural step b)7, the control and evaluation unit sets it off against the setpoint torque (M.sub.soll) to obtain a torque deviation (M.sub.Soll-M.sub.ist).

[0133] FIG. 5 shows in table b) the calculation formulas for the correction values (according to procedural step b)8) with the torque deviation on the basis of the interpolation distances (h, I) used, a learning constant (K.sub.Lern) and the torque deviation (M.sub.soll-M.sub.ist).

LIST OF REFERENCE NUMERALS

[0134] I electric-motor assembly [0135] II main body [0136] III driven group of accessories [0137] 1 electric motor [0138] 2 control and evaluation unit [0139] 3 data memory [0140] 4 current regulator [0141] 5 rotor angle sensor [0142] 6 torque evaluator [0143] 7 stator [0144] 8 rotor [0145] 9 motor coils [0146] 10 food-crushing mechanism