Method for avoiding stalled motor in a stand mixer with sensorless bldc drive

Patent metadata

Field	Value
Publication number	US-2024275324-A1
Application number	US-202318166873-A
Country	US
Kind code	A1
Filing date	Feb 9, 2023
Priority date	Feb 9, 2023
Publication date	Aug 15, 2024
Grant date	—

Abstract

A method for operating an appliance, such as a stand mixer, is provided. In one example implementation, the method can include operating a motor of the appliance in a first direction. The method can further include detecting, by a feedback system of the appliance, a first trigger condition. The method can further include, responsive to detecting the first trigger condition, operating the motor of the appliance in a second direction that is different than the first direction.

First claim

What is claimed is:

1 . A method for operating an appliance, the method comprising:
operating a motor of the appliance in a first direction; detecting, via a feedback system, a first trigger condition; and responsive to detecting the first trigger condition, operating the motor of the appliance in a second direction, the second direction being different than the first direction.

2 . The method of claim 1 , further comprising:
detecting, via the feedback system, a second trigger condition; and responsive to detecting the second trigger condition, operating the motor of the appliance in the first direction.

3 . The method of claim 1 , wherein the first trigger condition is indicative of a stall condition in the motor.

4 . The method of claim 1 , wherein the first trigger condition is based on a speed of the motor dropping below a speed threshold.

5 . The method of claim 2 , wherein the second trigger condition comprises an expiration of a period of time.

6 . The method of claim 1 , wherein detecting the first trigger condition further comprises:
detecting a target speed of the motor is within a threshold window; and responsive to detecting the target speed of the motor being within the threshold window, decreasing, via a controller of the feedback system, the target speed of the motor to about zero revolutions-per-minute.

7 . The method of claim 6 , wherein decreasing the target speed of the motor to about zero revolutions-per-minute comprises decreasing the target speed of the motor in a stepped manner.

8 . The method of claim 6 , wherein decreasing the target speed of the motor to about zero revolutions-per-minute comprises decreasing the target speed of the motor in a linear manner.

9 . The method of claim 1 , further comprising:
responsive to detecting the second trigger condition and operating the motor of the appliance in the first direction, detecting, via the feedback system, a third trigger condition; and responsive to detecting the third trigger condition, operating the motor of the appliance in the second direction, wherein the third trigger condition is indicative of a stall condition of the motor.

10 . The method of claim 1 , wherein the feedback system is a sensorless feedback system comprising a back-EMF observer, the back-EMF observer configured to provide data indicative of a position or a speed of the motor.

11 . The method of claim 1 , wherein:
the first direction is a clockwise direction; and the second direction is a counterclockwise direction.

12 . A stand mixer appliance, comprising:
a base; a housing pivotally mounted to the base; a motor assembly comprising a motor disposed within the housing; a mixer shaft rotatably mounted on the housing; and a controller operably coupled to the motor, the controller configured to:
operate the motor in a first direction;
detect a first trigger condition; and
operate the motor in a second direction in response to detecting the first trigger condition, wherein the first direction is different than the second direction.

13 . The stand mixer appliance of claim 12 , wherein the controller is further configured to:
detect a second trigger condition; and operate the motor in the first direction in response to detecting the second trigger condition.

14 . The stand mixer of claim 12 , wherein the first trigger condition is indicative of a stall condition of the motor.

15 . The stand mixer appliance of claim 12 , wherein the motor is a brushless direct current (BLDC) motor.

16 . The stand mixer appliance of claim 12 , wherein the motor is a permanent magnet synchronous motor (PMSM).

17 . The stand mixer appliance of claim 12 , wherein:
the controller further comprises a back-EMF observer configured to provide data indicative of a position or a speed of the motor; and the controller is configured to implement a field-oriented control (FOC) control scheme.

18 . A motor assembly for a stand mixer, the motor assembly comprising:
a motor, the motor comprising at least a rotor; a motor drive; a feedback system configured to obtain feedback measurements of one or more electrical characteristics from the motor; and a controller operably coupled to the motor, the controller configured to:
operate the motor in a first direction;
detect a first trigger condition; and
operate the motor in a second direction in response to detecting the first trigger condition, wherein the first direction is different than the second direction.

19 . The motor assembly of claim 18 , wherein the controller is further configured to:
detect a second trigger condition; and operate the motor in the first direction in response to detecting the second trigger condition.

20 . The motor assembly of claim 18 , wherein:
the motor is a brushless DC (BLDC) motor; and the feedback system is a sensorless feedback system comprising a back-EMF observer, the back-EMF observer configured to provide data indicative of a position or a speed of the motor.

Assignees

• Haier Us Appliance Solutions Inc

Inventors

• Latham Joseph Wilson

Classifications

• B01F35/333

  the rotation sense being changeable, e.g. to mix or aerate, to move a fluid forward or backward or to suck or blow · CPC title

• B01F35/2202

  Controlling the mixing process by feed-back, i.e. a measured parameter of the mixture is measured, compared with the set-value and the feed values are corrected · CPC title

• B01F27/805

  wherein the stirrers or the receptacles are moved in order to bring them into operative position; Means for fixing the receptacle · CPC title

• B01F35/212

  of the driving system data, e.g. torque, speed or power data · CPC title

• H02P21/36

  Arrangements for braking or slowing; Four quadrant control · CPC title