Patent Application
20090090032
The present invention relates generally to snow removal vehicles, and more particularly, to an apparatus and method for measuring and controlling a snow plow blade.
Snow removal vehicles typically include a plow blade that is mounted beneath the vehicle frame, either in front of the vehicle or between the front and rear wheels. In both the front-mounted and the underbody-mounted configurations, it can be difficult to see the plow blade from the driver's cab. Specifically, in a snow removal vehicle where the plow blade is mounted between the front and rear wheels, the plow blade is out of the driver's line of sight while the driver is facing the forward direction, requiring the driver to periodically turn around to look at the plow blade.
On a conventional snow removal vehicle, the angle of attack of the plow blade is variable depending on the speed of the vehicle, and the characteristics and location of the snow. Since these conditions can change during operation of the snow removal vehicle, the plow blade can require frequent adjustment. The driver typically adjusts the plow blade manually with a lever or joystick located in the driver's cab while visually monitoring the plow blade.
Since the driver must operate the lever and visually monitor the plow blade while operating the snow removal vehicle, the driver's attention can be diverted from driving the vehicle. In addition, the driver is often operating the snow removal vehicle in poor road conditions. The poor driving conditions and the manual adjustment of the plow blade provide an opportunity to improve the safety of the snow removal vehicle operation.
A plow blade assembly and a position adjustment system includes a plow blade mounted to a frame of a vehicle, and an actuator for adjusting the position of the plow blade relative to the frame of the vehicle. The actuator includes a position sensor for sensing an actual position of the plow blade and inputting the actual blade position to a computer, and a user input receiver for the user to input a desired position of the plow blade to the computer. The computer compares the actual position to the desired position and causes the actuator to move the plow blade to the desired position without user intervention.
Referring to
At least one scraper-mounting bracket 22 extends generally perpendicularly from the frame 14 for attaching a plow blade assembly 24 to the vehicle 10. In the embodiment of
Referring now to
A blade position sensor 34 is mounted on the plow blade assembly 24 to sense the position of the movable scraper platform 32 (therefore the position of the plow blade 26), with respect to a datum on the snow removal vehicle 10. A first end 36 of the position sensor 34 is attached to a bracket 38, which is fixed to the movable scraper platform 32, and a second end 40 is attached to the fixed mounting platform 30. Advantageously, the position sensor 34 is a linear sensor such as a potentiometer, however other position sensors are contemplated.
Unless stated otherwise, the angle of the plow blade 26 is measured with respect to the vehicle 10, such that at zero angle, the plane of the plow blade is generally transverse to the direction of movement of the vehicle. The angle of the plow blade 26 increases from zero as the blade is pivoted towards the left side or towards the right side of the vehicle 10 (for a vehicle driving on a road, towards the sides of the road). It is contemplated that other datum and measurement systems can be used.
The speed of the snow removal vehicle 10 and the angle of the plow blade 26 are factors that determine the direction that the plowed snow is thrown, as well as how far and how fast the plowed snow is thrown by the vehicle. For example, the faster the snow removal vehicle 10 moves, the further the plowed snow is thrown to the side of the vehicle. When the snow removal vehicle 10 runs faster or slower, the driver will typically adjust the plow blade 26 position to optimize the angle of the plow blade for a desired placement of removed snow. Further, when the snow removal vehicle 10 encounters snow drifts, the plow blade 26 may get inadvertently rotated from the desired orientation, requiring the driver to readjust the plow blade position.
A flowchart of a position feedback control system 42 for measuring and controlling the plow blade 26 on the snow removal vehicle 10 is shown in
Referring now to
The computer 44 outputs to an actuator 52 on the manifold 28, which is advantageously a solenoid on a hydraulic manifold. The manifold 28 moves the movable scraper platform 32 with respect to the fixed mounting platform 30 to change the position of the plow blade 26. The position sensor 34 senses the position of the plow blade 26, and inputs the actual position of the plow blade to the computer 44.
The computer 44 implements a control function between the user input, the vehicle speed, the blade position sensor input, and the output to the actuator 52. Specifically, the computer 44 reads the user command for a desired blade position, reads the blade position sensor input and the vehicle speed input. The computer 44 converts the sensor inputs into actual blade angle using a calculation or table. Advantageously, the computer 44 uses the following equation to calculate actual blade angle using a potentiometer as a blade position sensor 34:
where φ is the plow blade angle, h is the potentiometer original length, Δh is the change in potentiometer length, and r is the fixed distance between pivot point (the point about which the blade pivots with respect to the vehicle) and the location of attachment of the potentiometer to the plow blade 26.
After the computer 44 computes the actual plow blade angle, it compares the actual blade angle to the desired blade angle. If there is a difference in the two values, the computer 44 actuates the actuator 52, such as the solenoid on the hydraulic manifold to correct any error in blade position. The computer 44 broadcasts the actual blade position to the display panel 48, which provides visual feedback of the blade position to the user.
It is contemplated that the user can dial in a desired position/angle at any time during operation of the snow removal vehicle, and the computer 44 will automatically compare and automatically correct the position of the plow blade 26. Further, it is contemplated that the desired position/angle can be set in the computer 44 until changed by the user, or for specific durations of time. Alternately, the user could input a desired angle as a function of the speed of the snow removal vehicle 10.
Referring now to
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
