US20220104671A1

US20220104671A1 - A cleaning system comprising a system for preventing the motor from overheating and a method threfore

Info

Publication number: US20220104671A1
Application number: US17/428,431
Authority: US
Inventors: Kevin Pohlman
Original assignee: Techtronic Cordless GP
Current assignee: Techtronic Floor Care Technology Ltd
Priority date: 2019-02-06
Filing date: 2020-02-04
Publication date: 2022-04-07
Also published as: AU2020218752A1; CN113613537A; EP3920766A1; WO2020163336A1

Abstract

A cleaning system (100) including a body (105), a motor (140) supported by the body (100), a sensor (325) configured to sense a characteristic of the motor (140), the characteristic selected from a group consisting of current, voltage, and power. The system (100) further includes a controller (305). The controller (305) is connected to the motor 140 and the sensor (325). The controller (305) includes an electronic processor (330) and a memory (335). The controller (305) is configured to receive, from the sensor (325), a signal indicative of the characteristic of the motor (140), determine, based on the signal, an integral of the signal over time, and operate the motor (140) based on the integral of the signal over time.

Description

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/801,758, filed on Feb. 6, 2019, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments relate to tools, such as but not limited to, cleaning systems or cleaners.

SUMMARY

Tools, such as cleaners, may include one or more motors. During operation, the motor may overheat. Monitoring a temperature of the motor may prevent overheating. Existing methods of preventing overheating include hardware devices (such as a thermal cut-off) that cut off power to the motor when a predetermined temperature is met. Such hardware devices may add cost to tools.
Thus, one embodiment provides a cleaning system including a body, a motor supported by the body, a sensor configured to sense a characteristic of the motor, the characteristic selected from a group consisting of current, voltage, and power. The system further includes a controller. The controller is connected to the motor and the sensor. The controller includes an electronic processor and a memory. The controller is configured to receive, from the sensor, a signal indicative of the characteristic of the motor, determine, based on the signal, an integral of the signal over time, and operate the motor based on the integral of the signal over time.
Another embodiment provides a method of operating a cleaning system having a motor. The method includes receiving, from a sensor, a signal indicative of a characteristic of the motor selected from a group consisting of current, voltage, and power. Determining, via a controller and based on the signal, an integral of the signal over time, and operating the motor based on the integral of the signal over time.
Other aspects of the application will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a system according to some embodiments.

FIG. 2 is a side view of the system of FIG. 1 according to some embodiments.

FIG. 3 is a perspective view of the system of FIG. 1 according to some embodiments.

FIG. 4 is a block diagram of a control system of the system of FIG. 1 according to some embodiments.

FIG. 5 is a flow chart illustrating an operation of the system of FIG. 1 according to some embodiments.

FIG. 6 is a flow chart illustrating an operation of the system of FIG. 1 according to some embodiments.

FIG. 7 is a chart illustrating one or more characteristics of the system of FIG. 1 over time according to some embodiments.

FIG. 8 is a chart illustrating an integration of a characteristic of the system of FIG. 1 over time according to some embodiments.

DETAILED DESCRIPTION

Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The application is capable of other embodiments and of being practiced or of being carried out in various ways.
FIGS. 1 and 2 illustrate a system 100 according to some embodiments. The system 100 may be configured to clean a surface (for example, a floor such as a hardwood floor, a carpeted floor, upholstery, etc.). Although illustrated as a handheld vacuum cleaner, in other embodiments, the system 100 may be another type of vacuum, such as but not limited to, an upright vacuum cleaner or a stick vacuum cleaner. In yet another embodiment, the system 100 may be a power tool, such as but not limited to, a drill, a driver, and a circular saw.
The system 100 may include a housing 105 having a nozzle assembly 110 and a handle assembly 115. The nozzle assembly 110 may include a nozzle opening 120. The handle assembly 115 may include a handle 125 having a grip 130 for a user to grasp. The handle may further include a user-interface 127. As illustrated, in some embodiments, user-interface 127 includes a switch or button 129, or other operative interface. The handle assembly 115 may further include, and/or support, a canister 135. In some embodiments, the canister 135 may include a separator configured to remove dirt particles from an airflow drawn into the system 100 that is then collected by the canister 135. The separator may be a cyclonic separator, a filter bag, and/or another separator.
The system 100 may further include a suction motor 140 (FIG. 4) contained within a motor housing 145 of the housing 105. In some embodiments, the suction motor 140 is coupled to a suction source, such as but not limited to, an impeller or fan assembly driven by the suction motor 140. Air and/or debris is drawn through the nozzle opening 120 via the suction motor 140.
The housing 105 may further include a battery receptacle 150. The battery receptacle 150 is configured to physically and/or electronically couple to a battery pack 155. The battery pack 155 may be configured to supply power to the system 100 for operation. Alternatively or additionally, the system 100 may include a power cord configured to receive power from an AC power source (for example, an AC power outlet).
FIG. 3 illustrates the system 100 according to another embodiment. As illustrated, the system 100 may further include a base assembly 200. The base assembly 200 may include a floor nozzle 205. After entering through the floor nozzle 205, air and/or debris may pass through the nozzle opening 120, which may be in fluid communication with the separator and/or suction motor 140. In some embodiments, the base assembly 200 includes one or more wheels 210. In some embodiments, the base assembly 200 may further include a brush roll powered via a brush roll motor 215 (FIG. 4).
FIG. 4 is a block diagram of a control system 300 of the system 100 according to some embodiments. The control system 300 includes a controller 305. The controller 305 is electrically and/or communicatively connected to a variety of modules or components of the system 100. For example, the controller 305 is connected to the user-interface 127, suction motor 140, the brush roll motor 215, a power supply 310, an input/output (I/O) module 320, and one or more sensor 325.
In some embodiments, the controller 305 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller 305 and/or the system 100. For example, the controller 305 includes, among other things, an electronic processor 330 (for example, a microprocessor or another suitable programmable device) and the memory 335.
The memory 335 includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as read-only memory (ROM), random access memory (RAM). Various non-transitory computer readable media, for example, magnetic, optical, physical, or electronic memory may be used. The electronic processor 330 is communicatively coupled to the memory 335 and executes software instructions that are stored in the memory 335, or stored on another non-transitory computer readable medium such as another memory or a disc. The software may include one or more applications, program data, filters, rules, one or more program modules, and other executable instructions.
Power supply 310 is configured to supply nominal power to the controller 305 and/or other components of the system 100. As illustrated, in some embodiments, the power supply 310 receives power from the battery pack 155 and provides nominal power to the controller 305 and/or other components of the system 100. In other embodiments, the power supply 310 may receive power from an AC power source (for example, an AC power outlet).
The one or more sensors 325 are configured to sense one or more characteristics of the system 100. In some embodiments, the one or more sensors 325 include a voltage sensor, a current sensor, an ultrasonic sensor, an air flow sensor, a pressure sensor and/or an infrared sensor. In some embodiments, the one or more sensors 325 are configured to sense one or more characteristics (for example, a voltage, a current, and/or a power) of the suction motor 140 and/or brush roll motor 215.
In one embodiment of operation, a user operates the button 129 to activate the system 100. In such an embodiment, when button 129 is operated, power is provided to the suction motor 140 and/or brush roll motor 215. During operation, the one or more sensors 325 sense one or more characteristics (for example, a voltage, a current, and/or a power) of the suction motor 140 and/or brush roll motor 215.
FIG. 5 is a flowchart illustrating a process, or operation, 400 for operating system 100 according to some embodiments. It should be understood that the order of the steps disclosed in process 600 could vary. Furthermore, additional steps may be added and not all of the steps may be required. One or more characteristics of the suction motor 140 and/or brush roll motor 215 are sensed (block 405). A temperature of the suction motor 140 and/or brush roll motor 215 is determined based on the one or more sensed characteristics (block 410). In some embodiments, the temperature is determined by the controller 305. The temperature is compared to a temperature threshold (block 415). If the temperature crosses the threshold, the suction motor 140 and/or brush roll motor 215 is shut down (block 420). If the temperature does not cross the threshold, operation 400 cycles back to block 405.
FIG. 6 is a flowchart illustrating a process, or operation, 500 for determining a temperature of the suction motor 140 and/or brush roll motor 215 according to some embodiments. It should be understood that the order of the steps disclosed in process 600 could vary. Furthermore, additional steps may be added and not all of the steps may be required. A characteristic of the motor is sensed (block 505). In some embodiments, the characteristic is a current. In some embodiments, the characteristic is a power. In such an embodiment, the power may be determined by multiplying a sensed current and a sensed voltage. For example, FIG. 7 is a chart 600 illustrates a plurality of characteristics (a current 605, a voltage 610, a power 615, and a temperature 620) of a motor (for example, suction motor 140 and/or brush roll motor 215) over time.
An integral of the characteristic over a time period is then determined (block 510). In some embodiments, the integral is determined via the controller 305. For example, FIG. 8 is a chart 700 illustrating an integral of power versus temperature. The motor may then be controlled based on the integral of the characteristic over time (block 515). For example, if the integral crosses a predetermined threshold, operation of the motor may be halted.
In some embodiments, the temperature of the motor is determined based on the integral. In some embodiments, the temperature of the motor is determined using Equation 1 below.
Temp=Power×(1−Efficiency)−Heat dissipated by the system
Where, Temp=motor temperature, Power=integrated power, and Efficiency=motor efficiency curve. In some embodiments, the temperature of the motor is determined based on an area of the integral over time.
The heat dissipated by the system 100 may be estimated based on empirical information relating to the motor operating in the system 100, including temperature of the motor when drawing particular current levels at a predetermined ambient temperature. In one embodiment, the system 100 includes a thermistor positioned to represent the ambient air temperature that the system 100 is operating in, and wherein the heat dissipated by the system is a function of the ambient air temperature. For example, when calculating the heat dissipated by the system 100, the empirical data relating to the motor may be offset or compensated based on the ambient air temperature the system 100 is operating in.
Another factor in estimating the heat dissipated by the system 100 in some use scenarios is the length of time the motor is not operating, or cooling time, measured from when the motor was turned off, particularly if the cooling time is less than a predetermined interval, such as 3 minutes, or 5 minutes, or 10 minutes, or other predetermined interval. In one embodiment, the system 100 includes a timer that starts counting the cooling time after the motor is turned off. In this embodiment, if the motor is turned on within the predetermined interval, then the heat dissipated by the system 100 is a function of the cooling time. In another embodiment, the heat dissipated by the system 100 is a function of the cooling time and the ambient air temperature. The system 100 may include a battery or a hold-up capacitor that powers the timer after the motor is turned off. Alternatively, the system 100 may be a battery operated system 100 and the system battery powers the timer after the motor is turned off.
In some embodiments, operation of the motor may be halted when a max efficiency is met. However, in other embodiments, operation of the motor is based on the integral of the sensed characteristic, and thus the max efficiency may be surpassed and the motor still be allowed to operate.
Thus, embodiments provide, among other things, a system and method for operating a motor based on an integral of a characteristic of the motor over time. Various features and advantages of the application are set forth in the following claims.

Claims

What is claimed is:

1. A cleaning system comprising:

a body;

a motor supported by the body;

a sensor configured to sense a characteristic of the motor, the characteristic selected from a group consisting of current, voltage, and power; and

a controller connected to the motor and the sensor, the controlling including an electronic processor and a memory, the controller configured to

receive, from the sensor, a signal indicative of the characteristic of the motor,

determine, based on the signal, an integral of the signal over time, and

operate the motor based on the integral of the signal over time.

2. The cleaning system of claim 1, wherein operating the motor based on the integral of the signal over time includes prohibiting operation of the motor based on the integral of the signal over time.

3. The cleaning system of claim 1, wherein the controller is configured to determine, based on the integral of the signal over time, the temperature of the motor.

4. The cleaning system of claim 3, wherein the temperature of the motor is further determined based on an efficiency of the motor.

5. The cleaning system of claim 3, wherein the temperature of the motor is further based on a heat dissipated from the cleaning system.

6. The cleaning system of claim 5, wherein the heat dissipated from the cleaning system is a function of air temperature around the cleaning system.

7. The cleaning system of claim 5, wherein the heat dissipated from the cleaning system is a function of cooling time of the motor after the motor is turned off.

8. The cleaning system of claim 1, wherein characteristic is a power of the motor.

9. The cleaning system of claim 8, wherein the power of the motor is determined based on a current of the motor and a voltage of the motor.

10. The cleaning system of claim 1, wherein the motor is a brush roll motor.

11. The cleaning system of claim 1, wherein the motor is a suction motor.

12. The cleaning system of claim 1, wherein operating the motor based on the integral of the signal over time includes surpassing a max efficiency.

13. A method of operating a cleaning system having a motor, the method comprising:

receiving, from a sensor, a signal indicative of a characteristic of the motor selected from a group consisting of current, voltage, and power;

determining, via a controller and based on the signal, an integral of the signal over time; and

operating the motor based on the integral of the signal over time.

14. The method of claim 13, wherein the step of operating the motor based on the integral of the signal over time includes prohibiting operation of the motor based on the integral of the signal over time

15. The method of claim 13, further comprising determining a temperature of the based on the integral of the signal over time.

16. The method of claim 13, wherein characteristic is a power of the motor.

17. The method of claim 16, wherein the power of the motor is determined based on a current of the motor and a voltage of the motor.

18. The method of claim 13, wherein the motor is a brush roll motor.

19. The method of claim 13, wherein the motor is a suction motor.

20. The method of claim 13, wherein the step of operating the motor based on the integral of the signal over time includes surpassing a max efficiency.