Power tool having object detection
A power tool and methods are provided for detecting objects (e.g., flesh or other materials) in the operating path of a power tool's output component (e.g., saw blade or drill bit). An object detection sensor in the power tool generates an output signal indicative of a type of material detected in the operating path of the power tool. A power tool controller receives the object detection sensor output and determines when a material in the operating path of the power tool changes. The controller changes operation of a motor of the power tool (e.g., increasing or decreasing speed or stopping the motor) in response to the detected material change. The object detection sensor may include, for example, an RF sensor, a capacitive sensor, a camera, a conductivity probe, or an ultrasound probe.
1. A power tool comprising:
a housing;
a motor within the housing;
an output component coupled to the motor, the output component defining an operating path of the power tool;
an object detection sensor configured to generate an output signal indicative of an object being proximate to or in the operating path of the power tool; and
a controller connected to the motor and the object detection sensor, the controller including an electronic processor and a memory storing instructions that, when executed by the electronic processor, cause the electronic processor to:
receive the output signal from the object detection sensor,
determine, based on the output signal received from the object detection sensor, a type of material of an object proximate to or in the operating path of the power tool,
maintain, based on the determined type of material of the object proximate to or in the operating path of the power tool being a first type of material, an amount of electrical current available to the motor,
inhibit, based on the determined type of material of the object proximate to or in the operating path of the power tool being a second type of material, the amount of electrical current available to the motor, wherein the first type of material is different from the second type of material, and
increase, based on the determined type of material of the object proximate to or in the operating path of the power tool being a third type of material, the level of electrical current to the motor, wherein the third type of material is different from both the first type of material and he second type of material.
2. The power tool of claim 1 , wherein:
the second type of material is flesh, and
to inhibit the amount of electrical current to the motor, the instructions are further configured to cause the electronic processor to interrupt electrical current to the motor.
3. The power tool of claim 1 , wherein the second type of material includes at least one material selected from the group consisting of flesh, a part of a living being, and a liquid.
4. The power tool of claim 1 , wherein, to determine the type of material of the object proximate to or in the operating path of the power tool, the electronic processor is configured to:
analyze sensor information including at least one selected from the group consisting of a phase angle of the output signal, a frequency of the output signal, a dispersion pattern of the output signal, or a combination thereof; and
determine, based on the analyzed sensor information, the type of material of the object proximate to or in the operating path of the power tool.
5. The power tool of claim 1 , wherein:
the memory further stores a lookup table,
to determine the type of material of the object proximate to or in the operating path of the power tool, the instructions are further configured to cause the electronic processor to:
compare the output signal to thresholds or ranges stored in the lookup table in association with different types of materials, and
determine, from among the different types of materials in the lookup table, the type of material of the object proximate to or in the operating path of the power tool,
wherein a first output signal received from the object detection sensor indicates that the first type of material is proximate to or in the operating path of the power tool, and
wherein a second output signal received from the object detection sensor indicates the second type of material is proximate to or in the operating path of the power tool.
6. The power tool of claim 5 , wherein the thresholds or ranges stored in the lookup table include at least one selected from the group consisting of frequencies, phase differences, phase angles, capacitance measurements, conductivity measurements, and dispersion patterns.
7. The power tool of claim 5 , wherein:
the object detection sensor includes a radio frequency (RF) or ultrasound sensor that transmits a wideband frequency signal, and
the thresholds or ranges stored in the lookup table include frequencies, phase differences or dispersion patterns of RF or ultrasound sensor response signals.
8. The power tool of claim 5 , wherein:
the object detection sensor includes a capacitive sensor, and
the thresholds or ranges stored in the lookup table include capacitance measurements.
9. The power tool of claim 5 , wherein:
the object detection sensor includes a conductivity probe, and
the thresholds or ranges stored in the lookup table include conductivity measurements.
10. The power tool of claim 5 , wherein:
the object detection sensor includes a camera or camera array, and
to determine the type of material of the object proximate to or in the operating path of the power tool, the instructions are further configured to cause the electronic processor to:
receive image data in the output signal,
analyze the image data to extract light patterns associated with a particular object, and
determine the type of material of the object proximate to or in the operating path of the power tool based on the analysis of the extracted light patterns.
11. The power tool of claim 1 , wherein the instructions are further configured to cause the electronic processor to:
receive a user input that selects which type of materials detected by the object detection sensor cause what type of changes in the operation of the motor, and
update the lookup table in the memory based on the received user input.
12. A power tool comprising:
a housing;
a motor within the housing;
an output component coupled to the motor, the output component defining an operating path of the power tool;
an object detection sensor configured to generate an output signal indicative of an object being proximate to or in the operating path of the power tool; and
a controller connected to the motor and the object detection sensor, the controller including an electronic processor and a memory storing instructions that when executed by the electronic processor cause the electronic processor to:
detect a change in the output signal;
determine whether one of a first extraneous object, a second extraneous object, or a third extraneous object is proximate to or in the operating path of the power tool based on the change in the output signal; and
change an amount of electrical current available to the motor in response to determining which of the first extraneous object, the second extraneous object, or the third extraneous object is proximate to or in the operating path of the power tool,
wherein the first extraneous object is different from both the second extraneous object and the third extraneous object, and the second extraneous object is different from the third extraneous object.
13. The power tool of claim 12 , wherein, to detect the change in the output signal, the electronic processor is configured to:
analyze information including at least one selected from the group consisting of phase angles between two output signals, frequencies of the two output signals, dispersion patterns of the two output signals, or a combination thereof; and
based on detecting a change in the analyzed information, detect the change in the output signal.
14. The power tool of claim 12 , wherein, to change the amount of electrical current available to the motor, the electronic processor is configured to interrupt the electrical current to the motor.
15. The power tool of claim 12 , wherein the object detection sensor includes at least one selected from the group consisting of a radio frequency (RF) sensor, a capacitive sensor, a camera, a conductivity probe, and an ultrasound probe.
16. The power tool of claim 12 , further comprising a trigger, wherein the amount of electrical current is only supplied to the motor when the trigger is depressed.
17. A power tool controller comprising:
an electronic processor; and
a memory storing instructions that when executed by the electronic processor cause the electronic processor to:
receive an output signal from an object detection sensor,
determine, based on the output signal received from the object detection sensor, a type of material of an object proximate to or in the operating path of a power tool,
maintain, based on the determined type of material of the object proximate to or in the operating path of the power tool being a first type of material, an amount of electrical current available to a motor of the power tool,
inhibit, based on the determined type of material of the object proximate to or in the operating path of the power tool being a second type of material, the amount of electrical current available to the motor of the power tool, wherein the first type of material is different from the second type of material, and
increase, based on the determined type of material of the object proximate to or in the operating path of the power tool being a third type of material, the level of electrical current to the motor, wherein the third type of material is different from both the first type of material and the second type of material.
18. The power tool controller of claim 17 , wherein:
the second type of material is flesh, and
to inhibit the amount of current to the motor, the instructions are further configured to cause the electronic processor to interrupt the amount of electrical current to the motor.
19. The power tool controller of claim 17 , wherein
the memory further stores a lookup table,
to determine the type of material of the object proximate to or in the operating path of the power tool, the instructions are further configured to cause the electronic processor to:
compare the output signal to thresholds or ranges stored in the lookup table in association with different types of materials, and
determine, from among the different types of materials in the lookup table, the type of material of the object proximate to or in the operating path of the power tool,
wherein a first output signal received from the object detection sensor indicates that the first type of material is proximate to or in the operating path of the power tool, and
wherein a second output signal received from the object detection sensor indicates the second type of material is proximate to or in the operating path of the power tool.