EP3433055A1

EP3433055A1 - Electric tool and controlling method thereof

Info

Publication number: EP3433055A1
Application number: EP17769407.2A
Authority: EP
Inventors: Ning Yang; Hei Man LEE
Original assignee: TTI Macao Commercial Offshore Ltd
Current assignee: Techtronic Cordless GP
Priority date: 2016-03-22
Filing date: 2017-03-21
Publication date: 2019-01-30
Anticipated expiration: 2037-03-21
Also published as: AU2017239292A1; WO2017162130A1; CN108883522A; EP3433055A4; CN108883522B; EP3433055B1

Abstract

An electric tool includes a motor (12) for driving a working element, a controller (2) connected to the motor, a first user input device connected to the controller, and a memory (6) connected to the controller. The controller is configured to operate in a learning mode and an execution mode. In the learning mode the controller is adapted to record a varying pattern of operation of electric tool and store the varying pattern in the memory. In the execution mode, the controller is adapted to control the electric tool to operate without user intervention by replaying the varying pattern stored in the memory. With the learning mode, end users can pay less attention to the operation since the electric tool can replay the working process in the execution mode to prevent material being damaged for the same type of work.

Description

Electric Tool and Controlling Method Thereof

FIELD OF INVENTION
This invention relates to electric tools, and in particular motor-driven power tools.
BACKGROUND OF INVENTION
Hand-held electric tools are widely used in industrial and domestic applications. These electric tools are often designed for operating in corded or cordless mode, where the users use the electric tools to perform certain operations on a workpiece such as drilling, striking, grinding, and cutting. The mechanical force outputted by the electric tool comes from the electric motor installed in the electric tool, and the user actuates the electric tool via one or more user actuating means on the electric tool such as a switch, a trigger, or a lever.
However, one shortcoming associated with conventional electric tools is that most of these electric tools adopt only a simple control mechanism which requires the user to be highly concentrated all the time during the working process, since he/she has to manually and precisely control the electric tool during the entire operation. This is particular problematic in cases where a large number of repetitive operations is required, for example when fastening a lot of identical screws sequentially on a workpiece. Since such working process is tedious but consumes a long time, the user may easily get distracted soon after starting the work, and/or his/her hands and fingers become aching when trying to keep precise control of the electric tool by pressing a trigger. Once the user starts to lose concentrations during the repetitive operations, the outcome of these repetitive operations may become inconsistent, and in worse cases it may lead to accidents such as damages to the user.
SUMMARY OF INVENTION
In the light of the foregoing background, it is an object of the present invention to provide an alternate electric tool and its controlling method which eliminates or at least alleviates the above technical problems.
The above object is met by the combination of features of the main claim； the sub-claims disclose further advantageous embodiments of the invention.
One skilled in the art will derive from the following description other objects of the invention. Therefore, the foregoing statements of object are not exhaustive and serve merely to illustrate some of the many objects of the present invention.
Accordingly, the present invention, in one aspect, is an electric tool containing a motor for driving a working element, a controller connected to the motor, a first user input device connected to the controller, and a memory connected to the controller. The controller is configured to operate in a learning mode and an execution mode. In the learning mode, the controller is adapted to record a varying pattern of operation of the electric tool and store the varying pattern in the memory. In the execution mode, the controller is adapted to control the electric tool to operate without user intervention by replaying the varying pattern stored in the memory.
Preferably, the varying pattern contains variation of one or more parameters occurred during a period of time.
More preferably, the one or more parameters are selected from the group consisted of: current applied to the motor, voltage applied to the motor, number of steps that the motor has travelled in case the motor is a stepping motor； rotating speed of the motor, running time of the motor； degree of a user actuating the first user input device, and lasting time of the user actuating the first user input device.
According to one implementation, the first user input device is a trigger.
According to one variation of the embodiments, the controller is configured to record a number of repetitive profiles of operation of the electric tool in the learning mode； analyze the number of repetitive profiles； and produce an optimized profile as the varying pattern of operation of the electric tool.
Preferably, the controller is further configured to discard a profile from the number of repetitive profiles which has a maximum deviation.
Additionally /alternatively, the controller is further configured to average two or more profiles among the number of repetitive profiles to obtain the optimized profile.
According to one specific implementation, the number of repetitive profiles is the last ones among all repetitive profiles detected by the controller of the electric tool.
According to another implementation, the controller is switched between the learning mode and the execution mode by a user operating a second user input device of the electric tool.
Preferably, the second user input device is a press button or a switching clutch.
According to another aspect of the present invention, a method of controlling an electric tool includes the steps of placing the power tool in a learning mode, recording a varying pattern of operation of the electric tool by a controller of the electric tool, storing the varying pattern in a memory of the electric tool, placing the power tool in an execution mode； and replaying the operation of the electric tool by the controller according to the stored varying pattern without user intervention.
Preferably, the varying pattern comprises variation of one or more parameters occurred during a period of time.
More preferably, the one or more parameters are selected from the group consisted of: current applied to a motor of the electric tool, voltage applied to the motor, number of steps that the motor has travelled in case the motor is a stepping motor； rotating speed of the motor, running time of the motor； degree of the user actuating a first user input device, and lasting time of the user actuating the first user input device.
In one implementation, the first user input device is a trigger.
According to one variation of the preferred embodiments, the recording step further includes recording a number of repetitive profiles of operation of the electric tool by the controller of the electric tool； analyzing the number of repetitive profiles； and producing an optimized profile as the varying pattern of operation of the electric tool by the controller of the electric tool.
Preferably, the analyzing step comprises discarding a profile from the number of repetitive profiles which has a maximum deviation.
Additionally or alternatively, the producing step comprises averaging two or more profiles among the number of repetitive profiles to obtain the optimized profile.
Additionally or alternatively, the number of repetitive profiles is the last ones among all repetitive profiles detected by the controller of the electric tool.
According to another variation of the preferred embodiments, the method further contains, at the beginning, the steps of detecting whether a first user input device is actuated； determining whether the controller is placed under the learning mode or the execution mode, if the first user input device is actuated； and placing the electric tool to either the learning mode or the execution mode according to the determination result.
In another implementation, the controller is switched between the learning mode and the execution mode by the user operating a second user input device of the electric tool.
In yet another implementation, the second user input device is a press button or a switching clutch.
There are many advantages to the present invention, for example the user is now freed from having to precisely control the manual operation on the electric tool each time when performing repetitive works. Instead, the user only has to place the electric tool in the learning mode and performs manually the desired operation once. The behavior of the user’s operation and/or that of the electric tool is then recorded by the controller of the electric tool as a varying pattern, and stored in the on-board memory. For subsequent tasks which are repeating the first one, the user only needs to switch the electric tool into an execution mode, and the electric tool will precisely repeats the operation according to the varying pattern, without the need for user’s intervention. Therefore, a lot of effort by the user when using the electric tool can be saved and the user’s labor intensity is also reduced.
Another advantage of the present invention is that the recorded operation of the electric tool operation is not limited to a single and/or fixed parameter which may not be sufficient to replay the user’s operation precisely. Rather, the entire operation process of the user, and in particular any variation of the electric tool operation parameters, are recorded on a dynamic basis. Therefore, even for complicated operation processes during which the user’s operation and/or the motor operation status may be changing, the controlling method according to the present invention still allows a precise playback in the execution mode.
In addition, there is an Artificial Intelligent (AI) mechanism provided for the electric tool so that only the useful profiles among various profiles of operations are used to produce the varying pattern of operation to be recorded and executed (playback) . For example, one or more profiles which are apparently deviated from the rest of profiles can be automatically discarded, with the rest of the profiles be averaged to find out the optimal profile. Such a self-learning capability provided by the AI mechanism could avoid any inferior operation pattern due to misoperation of the user or when the user is still inexperienced in operating the electric tool, so that the recorded operation behavior is a readily useful one which could achieve a desired operation result.
BRIEF DESCRIPTION OF FIGURES
The foregoing and further features of the present invention will be apparent from the following description of preferred embodiments which are provided by way of example only in connection with the accompanying figures, of which:
Fig. 1 is an illustration of an electric tool internal structure according to a first embodiment of the present invention.
Fig. 2 shows the schematic circuit diagram of the electric tool in Fig. 1.
Fig. 3 shows a flow chart of the controller in the electric tool operating in a learning mode, according to an embodiment of the present invention.
Fig. 4 shows the flow chart of the controller in the electric tool in Fig. 3, when operating in an execution mode.
Fig. 5 shows a flow chart of the controller in the electric tool operating in two modes, according to a further embodiment of the present invention.
Fig. 6 is a chart showing five recorded profiles of the motor current versus time when main switch of the electric tool is pressed down, according to a further embodiment of the present invention.
Fig. 7 shows a flow chart of the controller in which multiple repetitive profiles are analyzed and processed to produce an optimized profile, according to a further embodiment of the present invention.
In the drawings, like numerals indicate like parts throughout the several embodiments described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
As used herein and in the claims, “couple” or “connect” refers to electrical coupling or connection either directly or indirectly via one or more electrical means unless otherwise stated.
Terms such as “horizontal” , “vertical” , “upwards” , “downwards” , “above” , “below” and similar terms as used herein are for the purpose of describing the invention in its normal in-use orientation and are not intended to limit the invention to any particular orientation.
Referring to Figure 1, according a first embodiment of the invention a portable power tool 10 which may be corded or cordless (battery-powered) portable device, such as a screwdriver or drill. The power tool 10 includes a housing 11, which accommodates most of the essential components for normal operation of the power tool 10 including the motor 12, a transmission gear assembly 13, an output shaft 15, a control circuit board 31, and a power supply module 17. The transmission gear assembly 13 is coupled between the motor 12 and the output shaft 15 to provide an altered output driving force for example with different speed and torque. The power supply module 17 can be a battery pack in the case of a cordless power tool, or it can be an AC-DC convertor in the case of a corded power tool where the power tool is connected to mains supply via a power cord (not shown) . A trigger 16 is configured on the housing 11 as a first user input device for the user to manually operate the power tool 10. In addition, a press button 18 is configured on the housing 18 as a second user input device to toggle the controller 2 between a learning mode and an execution mode. The control circuit board 31 carries electronic components such as a controller and a memory (which will be described below) .
Turning now to Fig. 2, the power tool contains a controller 2 which is connected to the motor 12 for controlling the operation of the latter. A memory 6 is also connected to the controller 2 for storing various operation information and parameters that are recorded by the controller 2. The trigger 16 and press button 18 are electrically connected to the controller 2 so that they can be used to accept inputs made by the user, and provide corresponding signals to the controller 2. The power supply module 17 is connected to the motor 12 and the controller 2 for powering these components in order for normal operation of the power tool.
The controller 2 is further connected to the motor 12 in a way that various motor status and operation parameters, in particular their variations, may be detected, measured, or otherwise obtained by the controller 2. In other words, a various pattern of these status and parameters may be recorded which contains not only a single value but also a dynamic variation of these status and parameters as time passes by. Such operation parameters include but not limited to working current of the motor 12, voltage applied to the motor 12, the rotation speed of the motor 12which is for example represented by revolution per minute (RPM) , output torque of the motor 12, etc. The output torque of the motor 12 may be either directly measured by using optical devices or mechanical torque measuring devices, or it may be measured indirectly based on the current of the motor 12. In case the motor 12 is a stepping motor, then the steps or angular positions that the motor that has traveled may also be detected by the controller 2. Temperature, such as that of the motor 12 or the power supply module 17, may also be detected as operation parameters.
On the other hand, the controller 2 is also adapted to monitor the user actuating behavior to the trigger 16. The user actuating behavior includes the lasting time that the user presses down the trigger 16, and the degree of such pressing action. As those skilled in the art would understand, the trigger of power tools are often designed to generate different control signals, for example on a linear basis, depending on to what extent the user presses down the trigger. If the user only presses the trigger slightly, that would leads to the trigger generating a signal with a smaller value. In the user presses the trigger heavily using a large force, then the trigger generates a signal with a larger value.
The varying pattern of the above detected or measured status and parameters can then be recorded by the controller 2 and saved in the memory 6. At a later time, the saved varying pattern may be loaded from the memory 6 by the controller 2 to reproduce the recorded operation of the electric tool.
Now turning to the operation of the device described above, Figs. 3 and 4 show how the electric tools according to the present invention may be placed in a learning mode in which the varying pattern mentioned above is recorded, and in an execution mode in which the electric tool is automatically operated to replay the recorded operation. Taking the example of an electric screwdriver, in Step 40 of Fig. 3 the user firstly switches the screwdriver into the learning mode by pressing for example the press button on the power tool described above. The controller is then initiated and made ready to record the power tool operation
The user in Step 42 then begins the operation by pressing down the trigger. The motor of the power tool is now activated and starts the operation on the workpiece. During such process, the controller in Step 44 records variation pattern of the power tool operation. For example, the degree of the user pressing on the trigger is monitored and recorded as time passes by. Such pressing degree may be varying as time passes. When the power tool initially drives the screw into the workpiece, the user only slightly presses the trigger since less torque is required. When the screw is consequently driven deep into the workpiece, the user presses down the trigger more as a larger torque is now required. Such variation of trigger operation process is monitored and recorded. Alternatively or additionally, other parameters may also be recorded such as the working current of the motor, the voltage applied to the motor, the rotation speed of the motor, the output torque of the motor 12, and the temperature of the motor /power supply module as mentioned above. These parameters may also exhibit a varying nature as time passes. Note that one or more of these parameters may be recorded at the same time in order to obtain a stored operation process of the power tool as precise as possible.
Later, the user finishes the operation of the power tool in Step 46 after the screw has been completed fastened into the workpiece at a desired depth. The user then releases the trigger so as to stop the motor operation. When the trigger is released, the controller 2 acknowledges such releasing action as a stop signal for the recording process of the varying pattern. As the last step of the learning mode, in Step 48 the entire varying pattern is then written into the memory of the power tool, which preferably does not lose even after the power tool is powered off.
When the user wishes to repeat the operation of fastening a second, third or even more identical screws, he/she can switch the power tool to the execution mode, in which the power tool is able to repeat or say replay the previously recorded operation process of the power tool without the need for the user to intervene. To start the automatic operation process, the user firstly switches the power tool to the execution mode in Step 50 for example by pressing the press button on the power tool again. Then, the user simply places the power tool into a read-to-work position, for example urges the screwdriver bit against the screw on the workpiece, and then presses the trigger once to initiate the automatic “playback” in Step 52. Note that in this step it is irrelevant if the user presses the trigger lightly or heavily, as such pressing action only serves as a start signal to the controller. The controller in Step 54 then starts to playback the recorded operation according to the varying pattern, for example by supplying a time-dependent control voltage and/or working current to the motor so that the output speed and torque of the motor is precisely controlled to resemble those when the user was manually controlling the power tool during the learning process. Once the recorded varying pattern is fully executed, the power tool automatically notifies the user about the completion of the automatic process in Step 56, for example by reducing tool speed, flashing a work light on the power tool housing, and/or stopping the motor. At last, in Step 58 the automatic operation is completed. The user may then start another repetitive operation by returning to Step 52 again, or placing the power tool in the learning mode for a different task.
According to a further embodiment of the present invention, a further operation method of the electric tool is provided which is slightly different from those in Figs. 3 and 4. Referring to Fig. 5, the method starts at Step 60 which could be the time when the electric tool is ready to be used. Then, in Step 62 a controller of the electric tool determines whether a main switch (e.g. a trigger) as a first user input device is pressed. If the main switch is not pressed, then the method goes directly to Step 70 where the method ends. However, if in Step 62 it is detected that the main switch is pressed and is kept in the pressed state (i.e. the user has not released his/her fingers) , then the method proceeds to Step 64 in which the controller determines whether the electric tool is placed in the learning mode or playback (i.e. execution) mode. Depending on the result of such determination, the method proceeds either to Step 66 in which the electric tool records a vary pattern of operation parameters similar to that in Fig. 3, or the method proceeds to Step 68 in which the electric tool playbacks the recorded varying pattern to automatically complete desired operation similar to that in Fig. 4. In Step 68, optionally the electric tool will remind the user when the work is about to be completed by, for example, reducing the motor output speed. After executing either Step 66 or 68, the method then goes to an end in Step 70.
Turning now to Figs. 6 and 7, in a modification of the embodiments shown in Fig. 4 or 5, the electric tool will record, update and fine tune the record varying pattern automatically as long as the electric tool is placed in the learning mode. This is referred as an Artificial Intelligent (AI) mechanism available at the electric tool. By way of example, Fig. 6 shows five recorded profiles 80, 82, 84, 86, 88 of the user’s operation on the main switch of the electric tool, with each profile representing a varying pattern every time the user has actuated the main switch. For five record profiles 80, 82, 84, 86, 88, the user has pulled the main switch for five times, and in each profile the variation of the motor current versus time elapsed is marked. In Fig. 7, after recording these profiles 80, 82, 84, 86, 88 in Step 90, the controller will analyze them and produce an optimized varying pattern for future playback. In particular, in Step 92 the controller will discard profile 82 because it takes less time than other profiles, which may indicates that the screw is not driven properly. The controller will also discard profile 84 because in this profile the motor current drops too much after startup, which is also different from other profiles. The profiles 82 and 84 are considered to have the maximum deviation from the rest of the profiles since one or more of the parameters (e.g. the instantaneous current drop, or persisting operation time) in the profiles 82 and 84b is most significantly different from that in the rest of the profiles. As a result, there are only three profiles 80, 86, 88 remained for further processing by the controller of the electric tool. The controller in Step 94 then takes an average of the three profiles 80, 86, 88, the result of which becomes an optimized profile in Step 96 that contains the varying pattern of operation of the electric tool for future playback /execution.
Note that the user may operate the main switch multiple times (e.g. more than five times) . If the controller is only to use five recorded profiles for analyzing and producing the optimized profile as mentioned, it means that some of the operations will not be used for analyzing. In one example, if the end-user operates the main switch in the learning mode, the controller will keep evaluating the latest several profiles (e.g. latest five profiles) on a dynamic basis, and continues to update the optimized profile as time goes by.In this way it can be expected that the single optimized profile will be improved gradually as the user continues to operate the electric tool, since it is likely that as the user uses the electric tool for longer and longer time, he /she will eventually find best way of operating the electric tool which is valuable for repeating by the electric tool automatically.
The exemplary embodiments of the present invention are thus fully described. Although the description referred to particular embodiments, it will be clear to one skilled in the art that the present invention may be practiced with variation of these specific details. Hence this invention should not be construed as limited to the embodiments set forth herein.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only exemplary embodiments have been shown and described and do not limit the scope of the invention in any manner. It can be appreciated that any of the features described herein may be used with any embodiment. The illustrative embodiments are not exclusive of each other or of other embodiments not recited herein. Accordingly, the invention also provides embodiments that comprise combinations of one or more of the illustrative embodiments described above. Modifications and variations of the invention as herein set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.
For example, in the exemplary embodiment described above, the user input device for toggling the electric tool between a learning mode and an execution mode is a press button. However, other types of devices may also be used such as a switch clutch to change the electric tool between the two modes.

Claims

An electric tool comprising:

a) a motor for driving a working element,

b) a controller connected to the motor,

c) a first user input device connected to the controller； and

d) a memory connected to the controller；

wherein the controller is configured to operate in a learning mode and an execution mode； in the learning mode the controller adapted to record a varying pattern of operation of the electric tool and store the varying pattern in the memory； in the execution mode, the controller adapted to control the electric tool to operate without user intervention by replaying the varying pattern stored in the memory.
The electric tool of claim 1, wherein the varying pattern comprises variation of one or more parameters occurred during a period of time.
The electric tool of claim 2, wherein the one or more parameters are selected from the group consisted of: current applied to the motor, voltage applied to the motor, number of steps that the motor has travelled in case the motor is a stepping motor； rotating speed of the motor, running time of the motor； degree of a user actuating the first user input device, and lasting time of the user actuating the first user input device.
The electric tool of claim 3, wherein the first user input device is a trigger.
The electric tool of claim 1, wherein the controller is further configured to record a number of repetitive profiles of operation of the electric tool in the learning mode； analyze the number of repetitive profiles； and produce an optimized profile as the varying pattern of operation of the electric tool.
The electric tool of claim 5, wherein the controller is further configured to discard a profile from the number of repetitive profiles which has a maximum deviation.
The electric tool of claim 5, wherein the controller is further configured to average two or more profiles among the number of repetitive profiles to obtain the optimized profile.
The electric tool of claim 5, wherein the number of repetitive profiles is the last ones among all repetitive profiles detected by the controller of the electric tool.
The electric tool of claim 1, wherein the controller is switched between the learning mode and the execution mode by a user operating a second user input device of the electric tool.
The electric tool of claim 3, wherein the second user input device is a press button or a switching clutch.
A method of controlling an electric tool, comprising the steps of:

a) placing the power tool in a learning mode；

b) recording a varying pattern of operation of the electric tool by a controller of the electric tool；

c) storing the varying pattern in a memory of the electric tool；

d) placing the power tool in an execution mode； and

e) replaying the operation of the electric tool by the controller according to the stored varying pattern without user intervention.
The method of claim 11, wherein the varying pattern comprises variation of one or more parameters occurred during a period of time.
The method of claim 12, wherein the one or more parameters are selected from the group consisted of: current applied to a motor of the electric tool, voltage applied to the motor, number of steps that the motor has travelled in case the motor is a stepping motor； rotating speed of the motor, running time of the motor； degree of the user actuating a first user input device, and lasting time of the user actuating the first user input device.
The method of claim 13, wherein the first user input device is a trigger.
The method of claim 11, wherein Step b) further comprises:

i. recording a number of repetitive profiles of operation of the electric tool by the controller of the electric tool；

ii. analyzing the number of repetitive profiles； and

iii. producing an optimized profile as the varying pattern of operation of the electric tool by the controller of the electric tool.
The method of claim 15, wherein the analyzing step comprises discarding a profile from the number of repetitive profiles which has a maximum deviation.
The method of claim 15, wherein the producing step comprises averaging two or more profiles among the number of repetitive profiles to obtain the optimized profile.
The method of claim 15, wherein the number of repetitive profiles is the last ones among all repetitive profiles detected by the controller of the electric tool.
The method of claim 11, further comprises the followings steps before Step a) :

i. detecting whether a first user input device is actuated；

ii. determining whether the controller is placed under the learning mode or the execution mode, if the first user input device is actuated； and

iii. proceeding to Step a) , or jumping to Step d) , according to the determination result of Step ii.
The method of claim 11, wherein the controller is switched between the learning mode and the execution mode by the user operating a second user input device of the electric tool.
The method of claim 20, wherein the second user input device is a press button or a switching clutch.