Methods to prevent wheel slip in an autonomous floor cleaner
First Claim
1. A robotic device for treating a surface, comprising:
- a first wheel driven by a first motor;
a second wheel driven by a second motor;
a housing supported by the first wheel and the second wheel;
means for measuring wheel rotation for the first wheel and the second wheel; and
a controller in communication with the first motor, the second motor, and the means for measuring wheel rotation, the controller receiving first wheel rotation signals associated with the first wheel from the means for measuring wheel rotation, the controller receiving second wheel rotation signals associated with the second wheel from the means for measuring wheel rotation, the controller providing first speed signals to the first motor for driving the first wheel, the controller providing second speed signals to the second motor for driving the second wheel, wherein the controller executes a stored program to;
(i) calculate a first amount of slip for the first wheel from the first wheel rotation signals received from the means for measuring wheel rotation, (ii) calculate a second amount of slip for the second wheel from the second wheel rotation signals received from the means for measuring wheel rotation, (iii) provide first speed signals to the first motor that slow or stop the first wheel if the first amount of slip exceeds a predetermined first value of slip, and (iv) provide second speed signals to the second motor that slow or stop the second wheel if the second amount of slip exceeds a predetermined second value of slip.
3 Assignments
0 Petitions
Accused Products
Abstract
Tread structures, wave motion navigational controls, and ramp up recovery controls are provided to an autonomous floor cleaner to reduce wheel slippage. The floor cleaner delivers liquid to the floor as part of the cleaning process. Wheels on the device are provided with relatively deep peripheral grooves to minimize the contact surfaces of a sprocket wheel and to accommodate the layer of liquid on the floor. In the event of wheel slippage, or to prevent wheel slippage, the device is designed to move forward with a slight side-to-side wave action caused by periodically altering the relative speeds of two drive wheels. There is also provided a slippage recovery mode where the drive wheels shut down or greatly slow when severe slippage is sensed, followed by a slow ramp up of speed.
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Citations
13 Claims
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1. A robotic device for treating a surface, comprising:
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a first wheel driven by a first motor;
a second wheel driven by a second motor;
a housing supported by the first wheel and the second wheel;
means for measuring wheel rotation for the first wheel and the second wheel; and
a controller in communication with the first motor, the second motor, and the means for measuring wheel rotation, the controller receiving first wheel rotation signals associated with the first wheel from the means for measuring wheel rotation, the controller receiving second wheel rotation signals associated with the second wheel from the means for measuring wheel rotation, the controller providing first speed signals to the first motor for driving the first wheel, the controller providing second speed signals to the second motor for driving the second wheel, wherein the controller executes a stored program to;
(i) calculate a first amount of slip for the first wheel from the first wheel rotation signals received from the means for measuring wheel rotation, (ii) calculate a second amount of slip for the second wheel from the second wheel rotation signals received from the means for measuring wheel rotation, (iii) provide first speed signals to the first motor that slow or stop the first wheel if the first amount of slip exceeds a predetermined first value of slip, and (iv) provide second speed signals to the second motor that slow or stop the second wheel if the second amount of slip exceeds a predetermined second value of slip. - View Dependent Claims (2, 3, 4)
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5. A robotic device for treating a surface, comprising:
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a first wheel driven by a first motor;
a second wheel driven by a second motor;
a housing supported by the first wheel and the second wheel;
means for measuring wheel rotation for the first wheel and the second wheel; and
a controller in communication with the first motor, the second motor, and the means for measuring wheel rotation, the controller receiving first wheel rotation signals associated with the first wheel from the means for measuring wheel rotation, the controller receiving second wheel rotation signals associated with the second wheel from the means for measuring wheel rotation, the controller providing first speed signals to the first motor for driving the first wheel, the controller providing second speed signals to the second motor for driving the second wheel, wherein the controller executes a stored program to;
(i) calculate a first amount of slip for the first wheel from the first wheel rotation signals received from the means for measuring wheel rotation, (ii) calculate a second amount of slip for the second wheel from the second wheel rotation signals received from the means for measuring wheel rotation, (iii) provide first speed signals to the first motor that cyclically decreases and increases speed of the first wheel if the first amount of slip has exceeded the predetermined first value of slip, and (vi) provide second speed signals to the second motor that cyclically decreases and increases speed of the second wheel if the second amount of slip has exceeded the predetermined second value of slip.
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6. A robotic device for treating a surface, comprising:
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a first wheel driven by a first motor;
a second wheel driven by a second motor;
a housing supported by the first wheel and the second wheel;
means for measuring wheel rotation for the first wheel and the second wheel; and
a controller in communication with the first motor, the second motor, and the means for measuring wheel rotation, the controller receiving first wheel rotation signals associated with the first wheel from the means for measuring wheel rotation, the controller receiving second wheel rotation signals associated with the second wheel from the means for measuring wheel rotation, the controller providing first speed signals to the first motor for driving the first wheel, the controller providing second speed signals to the second motor for driving the second wheel, wherein the controller executes a stored program to;
(i) calculate a first amount of slip for the first wheel from the first wheel rotation signals received from the means for measuring wheel rotation, (ii) calculate a second amount of slip for the second wheel from the second wheel rotation signals received from the means for measuring wheel rotation, and (iii) when the first amount of slip exceeds a predetermined first value of slip or the second amount of slip exceeds a predetermined second value of slip, provide first speed signals to the first motor and provide second speed signals to the second motor such that the device navigates in a wavy pattern. - View Dependent Claims (7)
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8. A robotic device for treating a surface, comprising:
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a first wheel driven by a first motor;
a second wheel driven by a second motor;
a housing supported by the first wheel and the second wheel;
means for delivering a fluid onto the surface;
means for measuring wheel rotation for the first wheel and the second wheel; and
a controller in communication with the first motor, the second motor, the means for delivering a fluid, and the means for measuring wheel rotation, the controller receiving first wheel rotation signals associated with the first wheel from the means for measuring wheel rotation, the controller receiving second wheel rotation signals associated with the second wheel from the means for measuring wheel rotation, the controller providing first speed signals to the first motor for driving the first wheel, the controller providing second speed signals to the second motor for driving the second wheel, the controller providing fluid delivery signals to the means for delivering a fluid, wherein the controller executes a stored program to;
(i) calculate a first amount of slip for the first wheel from the first wheel rotation signals received from the means for measuring wheel rotation, (ii) calculate a second amount of slip for the second wheel from the second wheel rotation signals received from the means for measuring wheel rotation, and (iii) when the first amount of slip exceeds a predetermined first value of slip or the second amount of slip exceeds a predetermined second value of slip, provide fluid delivery signals to the means for delivering a fluid such that fluid is not delivered onto the surface.
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9. A robotic device for treating a surface, comprising:
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a first wheel driven by a first motor;
a second wheel driven by a second motor;
a housing supported by the first wheel and the second wheel;
a sheet cleaning material disposed on the device;
means for delivering a fluid onto the sheet cleaning material;
means for measuring wheel rotation for the first wheel and the second wheel; and
a controller in communication with the first motor, the second motor, the means for delivering a fluid, and the means for measuring wheel rotation, the controller receiving first wheel rotation signals associated with the first wheel from the means for measuring wheel rotation, the controller receiving second wheel rotation signals associated with the second wheel from the means for measuring wheel rotation, the controller providing first speed signals to the first motor for driving the first wheel, the controller providing second speed signals to the second motor for driving the second wheel, the controller providing fluid delivery signals to the means for delivering a fluid, wherein the controller executes a stored program to;
(i) calculate a first amount of slip for the first wheel from the first wheel rotation signals received from the means for measuring wheel rotation, (ii) calculate a second amount of slip for the second wheel from the second wheel rotation signals received from the means for measuring wheel rotation, and (iii) when the first amount of slip exceeds a predetermined first value of slip or the second amount of slip exceeds a predetermined second value of slip, provide fluid delivery signals to the means for delivering a fluid such that fluid is not delivered onto the sheet cleaning material.
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10. A robotic device for treating a surface, comprising:
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a first wheel having a first tread and a second wheel having a second tread, the first tread and the second tread having grooves of a depth exceeding a predetermined depth;
a housing supported by the first wheel and the second wheel;
means for delivering a layer of fluid onto the surface, and a controller in communication with the means for delivering a fluid, the controller providing fluid delivery signals to the means for delivering a fluid such that the layer of fluid on the surface has a thickness less than the predetermined depth. - View Dependent Claims (11, 12, 13)
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Specification