System and method for road milling with adaptive cut-in speed

Abstract

The present disclosure relates to systems and methods for road milling with adaptive cut-in speed. A working machine includes a frame, a milling drum, a traction device, a pressure sensor, and a controller. The milling drum is connected to the frame. The traction device includes an actuator configured to controllably raise and lower the frame relative to a working surface. The pressure sensor is operably connected to the actuator and configured to measure a pressure of the actuator. The controller is communicatively connected to the pressure sensor and configured to receive information from the pressure sensor indicative of the pressure of the actuator and control a rate at which the milling drum is lowered into the working surface based on the pressure.

Description

Technical Field

[0001] This disclosure generally relates to systems and methods for road milling with adaptive cut-in speed. Background Technology

[0002] Milling or other operations that process roads or other terrain typically include a milling head that can be lowered to engage the surface being processed. Such operations include road milling and mixing machines, rotary mixers, and cold milling machines, which may generally be referred to in this disclosure as milling operations or milling machines.

[0003] Milling machinery lowers a rotating cutting head or drum into the surface of a road to cut and otherwise treat it. Milling machines can lower the cutting head at various controllable speeds, sometimes referred to as the infeed speed. The infeed speed can affect the quality of the road milling operation as well as other aspects of the operation of the milling machinery.

[0004] In some cases, cutting the cutting head into the road at too high a speed can result in equal and opposite upward forces of a magnitude large enough to undesirably reduce or lift one or more of the milling machine's traction devices due to various factors including the cutting depth and the material properties of the road (such as density and / or hardness).

[0005] U.S. Patent No. 10,386,866, entitled “Automatic Control of Plungevelociity Based on Depth of Cut,” discloses a system and method related to the automatic control of the cut speed of a milling machine based on the depth of cut. Summary of the Invention

[0006] An exemplary working machine includes a frame, a milling drum, a traction device, a pressure sensor, and a controller. The milling drum is connected to the frame. The traction device includes an actuator configured to controllably raise and lower the frame relative to a work surface. The pressure sensor is operatively connected to the actuator and configured to measure the pressure of the actuator. The controller is communicatively connected to the pressure sensor and configured to receive information from the pressure sensor indicating the pressure of the actuator, and to control the rate at which the milling drum descends into the work surface based on that pressure.

[0007] An exemplary method includes: receiving information from one or more pressure sensors indicating pressure of an actuator of a working machine, the working machine including a milling drum connected to a frame and a traction device including the actuator, the actuator being configured to controllably raise and lower the frame relative to a work surface; and controlling the rate at which the milling drum descends into the work surface based on the pressure.

[0008] These and other examples and features of the apparatus, system, and method will be set forth in part in the following detailed description. This overview is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. Detailed descriptions are included to provide further information regarding this patent application. Attached Figure Description

[0009] In accompanying drawings that are not necessarily drawn to scale, similar numbers may describe similar parts in different views. Similar numbers with different letter suffixes may represent different examples of similar parts. The accompanying drawings illustrate, by way of example and not limitation, the various embodiments discussed in this document.

[0010] Figure 1 A system including an exemplary milling machine according to this disclosure is schematically depicted.

[0011] Figure 2 It is a schematic depiction Figure 1 A block diagram of the system and the milling machine components.

[0012] Figure 3A and 3B An exemplary four-column rotary mixer working machine according to the present disclosure is schematically depicted.

[0013] Figure 4 An exemplary fixed chassis / frame rotary mixer working machine according to this disclosure is schematically depicted.

[0014] Figure 5 A flowchart is provided to depict an exemplary method according to this disclosure. Detailed Implementation

[0015] Figure 1 An exemplary system 100 according to this disclosure is depicted. System 100 includes milling machinery 102 at a work site for performing road milling operations in conjunction with multiple towing vehicles 104. The machinery 102 may include various types of milling machinery, such as cold milling machines and rotary mixers. Regardless of type, the machinery 100 may be operator-controlled, autonomous, or semi-autonomous machinery.

[0016] Milling machine 102 (which is in) Figure 1An example of a milling machine (which may be a cold milling machine) includes a frame 106 supported by one or more traction devices 108, a milling drum 110 rotatably supported below the belly of the frame 106, and an engine 112 mounted to the frame 106 and configured to drive the milling drum 110 and the traction devices 108. The traction devices 108 may include wheels or tracks connected to actuators 114 adapted to controllably raise and lower the frame 106 relative to the working surface 116. In an example according to this disclosure, raising and lowering the frame 106 may also be used to change the milling depth of the milling drum 110 into the surface 116. In an example, the milling machine 102 may include other mechanisms associated with the frame 106 and / or the milling drum 110 and configured to control the milling depth of the milling drum 110 and other parameters of the milling operation, including, for example, the cut speed / rate.

[0017] For example, the position of the frame 106 relative to the ground can remain constant, and the milling drum 110 can be operatively connected to actuators configured to raise and lower the milling drum relative to the working surface 116 and control other parameters such as milling depth and milling operation. In an example, the milling machine 100 may include a traction device 108 having actuators 114 that controllably raise and lower the frame 106 relative to the surface 116, and actuators operatively connected to the milling drum 110 to raise and lower the milling drum 110 relative to the surface 116 and / or the frame 106. One or more actuators may independently or in combination control parameters of the milling operation performed by the milling machine 100, including, for example, the cut speed of the milling drum 110.

[0018] exist Figure 1 In the example depicted, the milling machine 100 may be a cold milling machine. In this example, the traction device 108 may include wheels or tracks connected to an actuator 114, which is connected to a frame 106. The milling drum 110 may be fixedly connected to the frame 106. In the example where the milling machine 100 is a cold milling machine, the actuator 114 is adapted to controllably raise and lower the frame 106 relative to the working surface 116, which in turn is also used to raise and lower the milling drum 110 relative to the surface 116.

[0019] The exemplary system 100 also includes a controller or multiple controllers 118, which may be located somewhere on or away from the milling machine 102 and are communicatively connected to one or more components of the machine, including, for example, the milling drum 110 and actuator 114. Additionally, the controllers 118 may include multiple controllers located / assigned to different locations and communicatively connected to each other and connected to the milling machine 102. In this example, the controllers 118, whether on-board or remote from the machine 102, can be connected to various components of the machine and autonomously, semi-autonomously, or via operator input to control aspects of the machine's operation.

[0020] For example, multiple controllers 118 may be communicatively connected to the milling drum 110 and actuators 114, and configured to control the rate at which the milling drum 110 descends into the working surface 116 based on sensor input. The milling machine 102 may include, for example, one or more pressure sensors 120 associated with, connected to, and / or configured to measure the pressure of the actuators 114. In one example, each of the four (two forward / forward and two backward / reverse) actuators 114 of the milling machine 120 may include a pressure sensor 120 configured to measure the pressure of the corresponding actuator. Regardless of the number and specific arrangement, the multiple pressure sensors 120 may be communicatively connected to multiple controllers 118 and configured to send information (e.g., one or more analog or digital signals) indicative of the pressure of the actuators 114 to the multiple controllers, which may adjust the cut speed of the milling drum 110 based on said pressure.

[0021] The cut-in speed of the milling drum, or the rate at which the milling drum descends into the working surface, can affect several aspects of the machine's performance. For example, if the cut-in speed exceeds a certain threshold, the reaction force on the surface of the machine when the milling drum descends into it can exceed the weight of the machine. In other words, an excessively fast cut-in speed can reduce the load on one or more of the machine's traction devices, lift said one or more traction devices off the ground, or otherwise adversely reduce the load on the machine.

[0022] Although the cut-in speed of a milling drum can be measured and controlled in various ways, a simple way to control the cut-in speed to prevent unloading is to track the pressure of the actuator that raises and lowers the milling drum relative to the surface. Actuator pressure can serve as a relatively direct measure of unloading and allows for closed-loop control of the milling drum's cut-in speed without adverse effects such as mechanical unloading.

[0023] In an embodiment according to this disclosure, pressure sensors 120 may be configured to measure the pressure of one or more actuators 114 of the milling machine 102 and send information indicating the measured pressure to controllers 118. Controllers 118 may be configured to receive the information indicating the pressure of the actuators 114 and, based on that pressure, control the rate at which the milling drum 110 descends into the working surface 116.

[0024] The frame 106 of the milling machine 102 can also support an operator station 122. The operator station 122 can accommodate any number of input / output (I / O) devices and can include or communicatively connect to controllers 118. In some examples, the operator station 122 can be external to the milling machine 102. For example, the operator station 122 can be embodied as a remote control, such as a handheld controller, which the operator can use to control various aspects of the operation of the milling machine 102 from various locations. The operator station 122 can be implemented in software programs and associated user interfaces and can include a combination of hardware and software. In other embodiments, the milling machine 102 can be autonomous and may not include an operator station 122.

[0025] The exemplary system 100 may also include a conveyor system 124 pivotally connected at a front end to the frame 106 and configured to convey material away from the milling drum 110 and into a receiving portion such as a trailer 104. The conveyor system 124 may include a first conveyor 126 adjacent to the milling drum 110, the first conveying mechanism causing the milled material to be conveyed to a rear end 128 of a second conveyor 130. Conveyors 126 and 130 may each include a frame 132 and a conveyor belt 134 supported on a plurality of roller assemblies 136, including a headed roller assembly at the front end 138 of the second conveyor 130, and driven by a motor, which may be powered by an engine 112 or another power source.

[0026] As part of the milling operation, the milling machine 102 can mill the surface 116 of the road and transfer the milled material to a first tractor-trailer among a plurality of tractor-trailers (“tractor-trailers”) 104. In some cases, a second tractor-trailer may be in a standby position near the machine 102, and a third tractor-trailer may be located at or near a facility, such as an associated dispatch facility. Any number of tractor-trailers may be positioned near the milling machine 102 (e.g., in a standby position) and / or at an associated facility (e.g., awaiting dispatch). When full, a tractor-trailer 104 may leave from the machine 102 to deliver the milled material to the facility, and another tractor-trailer may approach the machine 102 to replace the tractor-trailer 104, so that the milling operation can continue.

[0027] Figure 2 A portion of an exemplary system 100 is schematically depicted, including a milling drum 110, an actuator 114, a plurality of controllers 118, and a plurality of pressure sensors 120. Additionally, the exemplary system 100 includes one or more I / O devices 200 associated with operator controls, including, for example, an operator station 122. The plurality of controllers 118 are communicatively connected to the plurality of pressure sensors 120 and the plurality of I / O devices 200. Furthermore, the plurality of controllers 118 are operatively connected directly or indirectly via one or more additional components of the system 100 to the actuators 114 and the milling drum 108 and configured to control aspects of the operation of the actuators and the milling drum. As an example, the actuators 114 may each include hydraulic cylinders configured to raise and lower the frame 106 of the milling machine 102 relative to the working surface 116. Such hydraulic cylinders may be part of the hydraulic system of the work machinery 102, which includes a fluid reservoir and a pump configured to pressurize hydraulic fluid and direct the pressurized fluid to the cylinder (and other hydraulically driven components of the hydraulic system). In an example, controllers 118 may be operatively connected to actuators 114 and configured to control the actuators via control of the pumps in the hydraulic system.

[0028] Multiple pressure sensors 120 are operatively associated with actuator 114, for example, connected to the actuator and / or arranged and configured to measure pressure in the actuator. Pressure sensors 120 may include various types of sensors, including absolute and / or differential pressure sensors. Additionally, pressure sensors 120 may employ different mechanisms to measure pressure in actuator 114. In examples, pressure sensors may include hermetically sealed, resistive, piezoelectric, capacitive, and / or optical pressure sensors.

[0029] The multiple I / O devices 200 may include various types of devices for displaying or otherwise outputting information and for inputting information and / or control commands. For example, the multiple I / O devices 200 may be configured to present the position of the milling machine 102 and the milling drum 110 relative to features of the work site (e.g., milled and / or unmilled portions of surface 116) and display data and / or other information to the operator, such as the type of pavement material to be milled by the milling drum 110, the available depth of cut for a particular milling machine and milling drum, and the available cut speed or rate at which the milling drum can be lowered or is being lowered into the pavement surface of a particular material and for a particular depth of cut. Additionally, the multiple I / O devices may be configured to receive data and / or control commands from the operator of the milling machine 102.

[0030] In this example, the (multiple) I / O devices 200 may include, in particular, a display and one or more other analog and / or digital input devices (including a keyboard, mouse, touchpad, and / or touchscreen). For example, the (multiple) I / O devices 200 may include analog input devices that receive control commands via one or more buttons, switches, dials, levers, etc. The (multiple) I / O devices 200 may also include, or alternatively include, digital components such as one or more soft keys, touchscreen icons, and / or visual displays, including various icons that can be activated by touching on various displays / touchscreens.

[0031] Multiple I / O devices 200 can be configured to generate one or more signals indicating various parameters associated with the milling machine 102 and / or its surrounding environment based on inputs received from the operator and / or data received from outside the machine (e.g., from a control center or other database accessible via a wireless network through the cloud). For example, multiple I / O devices 200 can be configured to receive inputs indicating the density and type of the milled material, as well as parameters of the haul vehicle 104 and the machine 102 (e.g., the size, volumetric capacity, weight capacity, legal weight limit, and type of the cutting tool mounted on the milling drum 110, the range of rotational speeds that can drive the milling drum 110, the desired depth of cut, the available and / or threshold cut speeds of the milling drum 110 (in some cases, corresponding to different depths of cut and the material being milled), etc.).

[0032] For reference Figure 1Generally described, the pressure sensors 120 can be configured to measure the pressure of one or more actuators 114 of the milling machine 102 and send information indicating the measured pressure to the controllers 118. The pressure measurements acquired by the pressure sensors 120 and on which the controllers 118 control the cut speed of the milling drum 110 can be derived from one or more actuators 114. In one example, the controllers 118 control the cut speed of the milling drum based on the pressure of the two front actuators 114, as these can more directly affect the quality of the cuts made by the milling drum 110 of the milling machine 100. Regardless of the number or specific combination of actuator pressures used, the controllers 118 can be configured to receive information indicating the pressure of the actuators 114 and control the rate at which the milling drum 110 descends into the working surface 116 based on that pressure.

[0033] For example, controller(s) 118 may receive information indicating the pressure of actuator(s) 114 from pressure sensors(s) 120 and compare the pressure of actuator(s) 114 with a threshold pressure. Controller(s) 118 may then control the rate at which the milling drum 110 descends into the working surface 116 based on this comparison. In an example, a threshold pressure may be determined and set as the pressure at which the milling machine 102 will become or may become undesirably unloaded. As an example, this threshold pressure may be stored in the memory of controller(s) 118 and read by controller(s). If controller(s) 118 determines that the pressure of one or more actuators 114, as measured by pressure sensors(s) 120, exceeds the threshold pressure, the controller may be configured to change the rate at which the milling drum 110 descends into the working surface 116.

[0034] For example, controller 118 may be configured to reduce the cut-in speed of milling drum 110 if one or more actuators in the comparison of measured pressure with threshold pressure indicates that the load becomes or may become unfavorably reduced. Conversely, controller 118 may be configured to maintain or increase the cut-in speed of milling drum 110 if one or more actuators in the comparison of measured pressure with threshold pressure indicates that the load does not become or may not become unfavorable.

[0035] The actuator 114 pressure information on which the (multiple) controllers 118 control the cut-in speed of the milling drum 110 can be absolute pressure or other pressure measurements. For example, the (multiple) controllers 118 can control the rate at which the milling drum 110 descends into the working surface 116 based on the pressure change and / or rate of pressure change of the actuator 114.

[0036] In this example, the controller(s) 118 may receive information indicating multiple pressures of the actuator 114 from the pressure sensors(s) 120 at multiple different times. The controller(s) 118 may determine pressure changes in the actuator based on the multiple pressures of the actuator 114. The controller(s) 118 may then control the rate at which the milling drum 110 descends into the working surface 116 based on the pressure changes. For example, the controller(s) 118 may compare the pressure changes of the actuator 114 with a threshold pressure change and control the rate at which the milling drum 110 descends into the working surface 116 based on that comparison.

[0037] In this example, the controller(s) 118 may receive information indicating multiple pressures of the actuator 114 from the pressure sensors(s) 120 at multiple different times. The controller(s) 118 may determine the rate of pressure change of the actuator 114 based on these multiple pressures. The controller(s) 118 may then control the rate at which the milling drum 110 descends into the working surface 116 based on the rate of pressure change of the actuator 114. For example, the controller(s) 118 may compare the rate of pressure change of the actuator 114 with a threshold rate of pressure change and control the rate at which the milling drum 110 descends into the working surface 116 based on this comparison.

[0038] Threshold pressures, including absolute pressure values ​​and pressure variations or rates of change, can be implemented in various ways. For example, threshold pressures can vary depending on the specific milling machine and / or site / operating environment, and can be pre-programmed into the memory of controller(s)118 or another component of system(s)100. Additionally, multiple threshold pressures can be made available for a specific machine, and can be selected, for example, by an operator via multiple I / O devices 200 of operator station(s)122.

[0039] The comparison of the threshold pressure with the pressure of one or more actuators 114 measured by the pressure sensors 120 can vary depending on how the pressure is measured. In an example, the actuator 114 may be a hydraulic cylinder, and the pressure sensors 120 may be arranged and configured to measure the pressure at the head and rod ends of one or more actuators 114. For example, a first pressure sensor may be configured to measure the pressure at the head end of one actuator 114, and a second pressure sensor 120 may be configured to measure the pressure at the rod end of the actuator. In an example, the controller 118 calculates a measured differential pressure equal to the head pressure measured by the pressure sensors 120 minus the rod pressure. In this example, if the controller 118 determines that the differential pressure of one or more actuators 114 measured by the pressure sensors 120 is less than the threshold differential pressure, the controller may be configured to reduce the rate at which the milling drum 110 descends into the working surface 116.

[0040] However, in another example, the pressure sensors 120 may be arranged and configured to measure the pressure at the head and rod ends of one or more actuators 114, and the controller 118 may calculate a measured differential pressure equal to the rod pressure measured by the pressure sensors 120 minus the head pressure. In this example, if the controller 118 determines that the differential pressure measured by the pressure sensors 120 of one or more actuators 114 is greater than a threshold differential pressure, the controller may be configured to reduce the rate at which the milling drum 110 descends into the working surface 116.

[0041] In this example, the rate at which the milling drum 10 descends into the working surface 116 can be controlled, in different ways, based on pressure by multiple controllers 118. In this example, the multiple controllers 118 can be configured to initially control the milling drum 110 to descend into the working surface at a default rate, which may be a relatively low rate. The multiple controllers 118 then receive information from multiple pressure sensors 120 indicating the pressure of the multiple actuators 114, and, for example, change the rate at which the milling drum 110 descends into the working surface 116 based on pressure by comparing the measured pressure to a threshold.

[0042] In another example, the controller(s) 118 may be configured to determine the maximum cut-in speed of the milling drum 110. For example, the controller(s) 118 may be configured to change the rate at which the milling drum 110 descends into the working surface 116. In this example, the controller(s) 118 incrementally increases the rate at which the milling drum 110 descends into the working surface 116 while also receiving information from the pressure(s) 120 indicating the pressure of the actuator 114 and comparing the pressure to a threshold. When the measured pressure reaches the threshold pressure, the controller(s) 118 may set a constant rate at which the milling drum 110 descends into the working surface 116.

[0043] As mentioned above, the manner in which the milling drum is cut into / lowered into the working surface on a milling machine can vary depending on the machine. For example, on a cold milling machine, the machine frame / chassis can be coupled to a movable actuator, and the milling drum can be fixedly coupled to the frame. The actuator of the cold milling machine is configured to raise and lower the machine, and thus raise and lower the milling drum.

[0044] In its example 300, it is depicted in Figure 3A and 3B In the four-column rotary mixer, the mechanical frame is movable relative to the working surface, and the milling drum is movable relative to both the frame and the working surface. (Reference) Figure 3A The four-column rotary mixer 300 may include a frame 302 extending from a first end 304 of the rotary mixer to a second end 306. The frame 302 is supported on a traction device 308 (one of which is located at...). Figure 3A (Not visible in the image), the traction device may take the form of wheels as in the illustrated example, or tracks as in other examples. Frame 302 is connected to traction device 308 via leg actuators 310. The height of one or more of the leg actuators 310 is adjustable, allowing the height of frame 302 relative to one or more of traction device 308 and working surface 312 to be increased or decreased by adjusting the length of one or more of the actuators 310.

[0045] The rotary mixer 300 includes a milling drum 314 attached to a frame 302 via arms 316. Arms 316 include a pair of arms positioned on either side of the four-column rotary mixer 300. Figure 3A Only one arm is visible in the milling drum 314, which includes cutting tools / teeth 318. The milling drum 314 may be enclosed within a drum chamber 320, which helps to contain material removed from the working surface 310 by the teeth 318. Rotation of the milling drum 314 causes the removed material to transfer from the adjacent front end 322 of the drum chamber 320 toward the rear end 324.

[0046] The four-column rotary mixer 300 includes an engine 326 and an operator platform 328. The engine 326 can be any suitable type of internal combustion engine, such as a gasoline, diesel, natural gas, or hybrid engine. Alternatively, the engine 326 can be electrically driven. The engine 326 can be configured to deliver rotational power output to (e.g.,) multiple hydraulic motors associated with a traction device 308, actuator 310, and milling drum 314, and to deliver power to other components or accessory devices of the rotary mixer 300.

[0047] Figure 3B It shows Figure 3A Parts and components of the 300 four-column rotary mixer, not visible in the image. (Reference) Figure 3B Arm 316 includes a left arm 330 disposed on the left side 332 of the rotary mixer 300 and a right arm 334 disposed on the right side 336. The left arm 330 and right arm 334 can be pivotally attached to the frame 302 and configured to rotate relative to the frame. The left arm 330 and right arm 334 can have a common pivot axis 338 disposed transversely to and generally parallel to the width direction of the frame 302. A cross tube or shaft 340 can be fixedly connected at one end to the left arm 330 and at the opposite end to the right arm 334. An arm actuator 342 can be connected between the frame 302 and the cross tube 340. For example, one end 344 of the arm actuator 342 is connected to the frame 302, and the opposite end 346 of the arm actuator 342 is connected to the cross tube 340. The arm actuator 342 may include various actuators, including, for example, single-acting or double-acting hydraulic or pneumatic actuators, rack and pinion devices, belt and pulley devices, etc.

[0048] In an embodiment according to this disclosure, the height of the milling drum 314 of the four-column rotary mixer 300 relative to the working surface 310 can be adjusted by rotating the arm 316 and / or by adjusting one or more of the leg actuators 310. Raising and lowering the milling drum 314 via the leg actuators 310 and / or arm actuators 342 can be used to change other parameters of the milling depth and milling operation, including, for example, the cut speed / rate. The cut speed of the milling drum 314 can be controlled to prevent unloading, for example, by tracking the pressure of the actuators that raise and lower the milling drum relative to the surface (e.g., by tracking the pressure of the leg actuators 310 and / or arm actuators 342).

[0049] In this example, the controller or multiple controllers 360 may be located somewhere on or away from the rotary mixer 300 and communicatively connected to one or more components of the machine, including, for example, the milling drum 314, the leg actuator 310, and / or the arm actuator 342. The controllers 360 may include multiple controllers located / assigned to different locations and communicatively connected to each other and connected to the rotary mixer 300. In this example, the controllers 360, whether on-board or away from the rotary mixer 300, may be connected to various components of the machine and autonomously, semi-autonomously, or via operator input to control aspects of the machine's operation.

[0050] Multiple controllers 360 may be communicatively connected to the milling drum 314, leg actuators 310, and / or arm actuators 342, and configured to control the rate at which the milling drum 314 descends into the work surface 312 based on sensor input. The rotary mixer 300 may include, for example, one or more leg pressure sensors 362 associated with, connected to, and / or configured to measure the pressure of the leg actuators 310, and / or one or more arm pressure sensors 364 associated with, connected to, and / or configured to measure the pressure of the arm actuators 342. Regardless of the number and specific arrangement, the leg pressure sensors 462 and / or the arm pressure sensors 464 are communicatively connected to the controllers 360 and configured to send information (e.g., one or more analog or digital signals) indicative of the pressure of the leg actuators 310 and / or the arm actuators 342 to the controllers, which can then adjust the cut speed of the milling drum 314 based on said pressure.

[0051] In its instance 400 Figure 4 In the fixed-chassis rotary mixer depicted, the mechanical frame can be fixed relative to the working surface, and the milling drum can be configured to rise and fall relative to the working surface. Figure 4 In this process, the rotary mixer 400 is configured to remove, recycle, or reuse a working surface layer 402, such as pavement, concrete, asphalt, or other materials, by penetrating into and breaking the working surface during a milling operation. The broken material can be redeposited on the working surface 402, where it can be used as subgrade or base aggregate in subsequent paving operations.

[0052] The rotary mixer 400 may include a frame 404 oriented such that a front end 406 and a rear end 408 are aligned along the direction of travel 410 of the machine; however, since the rotary mixer 100 can operate in both forward and reverse directions, the designation is used herein primarily for illustrative purposes. The frame 104 may be supported on a plurality of towing devices 412. In the illustrated embodiment, the towing device 412 is a rotatable wheel that may include rubber-filled pneumatic tires. In other instances, the fixed-chassis rotary mixer 400 includes a continuous track, such as a closed track arranged around rollers and / or sprockets, wherein translation of the track drives the rotary mixer above the working surface 402.

[0053] To power the traction device 412 and other systems of the rotary mixer 100, a power source, such as an internal combustion engine 414, can be mounted on the frame 404. The rotational output of the engine 414 can be transmitted via a crankshaft extending from the engine and is operatively associated with the traction device 412 and other systems. For example, the engine 414 can be operatively coupled to and drive other power systems on the rotary mixer 400, such as a mechanohydraulic system including one or more hydraulic pumps 416 for pressurizing hydraulic fluid and directing the hydraulic fluid through hydraulic conduits (such as hoses or lines). In one example, the traction device 412 may be hydrostatically driven and operatively associated with a hydraulic motor fluidly coupled to the hydraulic pump 416 to receive pressurized hydraulic fluid from there to rotate the wheel. Another exemplary system that can be included in the rotary mixer 100 and powered by the internal combustion engine 414 may be an alternator or generator 418 that generates electricity for an electrical system.

[0054] To accommodate an operator, the rotary mixer 400 may include an onboard operator's cab or operator station 419 on the frame 404 at a location providing visibility above and around the work surface 402 for milling operations. The operator station 419 may include various controls, reading devices, and other input / output interfaces and instruments for monitoring and controlling the operation of the rotary mixer 400, such as a steering joystick or steering handle for adjusting the direction of travel of the rotary mixer, speed controls for adjusting the travel speed of the rotary mixer, and controls for adjusting other systems associated with the rotary mixer, such as hydraulic pump 416 and generator 418. In other instances, the rotary mixer 400 may be configured for remote operation, and some or all of the aforementioned operator controls may be located remotely from the onboard operator station 419.

[0055] To engage and break up the working surface 402, the fixed-chassis rotary mixer 400 may include a milling drum 420 rotatably mounted on and supported by a frame 404. The milling drum 420 may be a drum-shaped cylindrical structure having a plurality of picks or toothed cutting tools 422 arranged around its cylindrical surface. The milling drum 420 is rotatable about a rotor axis 424, which is generally perpendicular to the direction of travel 410 and extends between a first lateral side and a second lateral side of the mechanical frame 404.

[0056] To accommodate broken material and debris, the milling drum 420 can be rotatably housed in a box-shaped housing or rotor enclosure 426, which extends from the frame 404 toward the working surface 402. The rotor enclosure 426 may be made of multiple metal plates and defines an encapsulation space 428 in which the milling drum 420 is located.

[0057] To vertically raise and lower the milling drum 420 relative to the working surface 402, a piston 430 may be located on each lateral side of the rotary mixer 400 and may be connected between the mechanical frame 404 and the drive belt / chain housing 446. In one example, the piston 430 may be operatively associated with a hydraulic system on the rotary mixer 400 and may be fluidly connected to a hydraulic pump 416 via hydraulic lines. Directing pressurized hydraulic fluid to and from the piston causes it to expand or contract telescopically, thereby increasing or decreasing the length of the piston extending between the mechanical frame 404 and the belt / chain housing 446. Thus, the milling drum 420 pivots or tilts about a pivot connection 432 and contacts and penetrates the working surface 402 during milling operations, and the depth of milling cut can be controlled by selectively adjusting the extension of the hydraulic piston 430.

[0058] To induce rotation, the cutting rotor 420 of the rotary mixer 400 is operatively coupled to an internal combustion engine 414 via an assembly of a component referred to as a drivetrain 434. The drivetrain 434 may include a drive shaft 436 connected at the rear of the engine to the crankshaft of the internal combustion engine 414 via a flywheel-clutch combination. The drive shaft 436 may be coupled to an axle 440 via a differential 438 or a similar gear train. The axial end of the axle 440 may be formed as a sprocket or pulley adapted to engage with one or more rotor drive belts or chains 442 extending to and passing around the rotor hub 444. The drive belts / chains 442 transmit the mechanical power of rotation from the axle 440 to the rotor hub 444, causing the cutting rotor 420 to rotate. In an example, the rotary mixer 400 may be configured to operate the cutting rotor 420 at different speeds and / or torques via a rotor drive transmission 450.

[0059] In an embodiment according to this disclosure, raising and lowering the milling drum 420 via piston 430 can be used to change other parameters of the milling depth and milling operation, including, for example, the infeed speed / rate. The infeed speed of the milling drum 420 can be controlled to prevent unloading, for example, by tracking the pressure of the actuator that raises and lowers the milling drum relative to the surface (e.g., by tracking the pressure of piston 430).

[0060] In this example, the controller or multiple controllers 460 may be located somewhere on or away from the rotary mixer 400 and communicatively connected to one or more components of the machine, including, for example, the milling drum 420 and / or the piston 430. The controllers 460 may include multiple controllers located / assigned to different locations and communicatively connected to each other and connected to the rotary mixer 400. In this example, whether on-board or away from the rotary mixer 400, the controllers 460 may be connected to various components of the machine and autonomously, semi-autonomously, or via operator input to control aspects of the machine's operation.

[0061] Multiple controllers 460 are communicatively connected to the milling drum 420 and the piston 430, and configured to control the rate at which the milling drum 420 descends into the working surface 402 based on sensor input. The rotary mixer 400 may include, for example, one or more pressure sensors 462 associated with, connected to, and / or configured to measure the pressure on the piston 430. Regardless of the number and specific arrangement, the multiple pressure sensors 462 may be communicatively connected to the multiple controllers 460 and configured to send information (e.g., one or more analog or digital signals) indicative of the pressure on the piston 430 to the multiple controllers, which may adjust the cut rate of the milling drum 420 based on said pressure.

[0062] Industrial applicability

[0063] Figure 5 A flowchart illustrating an exemplary method 500 according to an example of this disclosure is provided. Exemplary method 500 includes receiving information from a pressure sensor indicative of pressure on an actuator of a working machine (502), and controlling the rate at which a milling drum descends into the work surface based on the pressure (504). The working machine may be a milling machine comprising a milling drum connected to a frame and a traction device including an actuator. The actuator may be configured to controllably raise and lower the frame relative to the work surface.

[0064] In this example, the operator of machine 102 controls aspects of the machine's operation via operator station 122. The operator prepares to begin cutting the working surface 116 with the milling drum 110. Using multiple I / O devices 200, the operator configures various parameters of the milling operation, including, for example, depth of cut and feed rate. In this example, the operator selects the depth of cut for the milling operation. Multiple controllers 118 then present the operator with multiple different options for the feed rate of the milling drum 110 at the selected depth of cut, for example, via a display device of the multiple I / O devices 200. For example, the multiple controllers 118 may request the operator to input a threshold pressure (including absolute pressure value, pressure variation, or rate of change of pressure) for one or more actuators 114; above this threshold pressure, the multiple controllers 118 will automatically reduce the feed rate of the milling drum 110. In this example, the multiple controllers 118 present multiple different possible threshold pressure values ​​for the operator to select. In this example, controller(s) 118 displays one or more of the aforementioned options, and also displays an option to determine the maximum cut-in speed of the milling drum 110. Under this option, controller(s) can be configured to increase the rate at which the milling drum 110 descends into the working surface 116 from a default rate, for example incrementally, while also receiving information from pressure sensors(s) 120 indicating the pressure of actuator 114 and comparing the pressure to a threshold. When the measured pressure reaches the threshold pressure, controller(s) 118 can set a constant rate (a determined maximum value) at which the milling drum 110 descends into the working surface 116.

[0065] In this example, the operator selects a threshold pressure for the actuator 114 based on inputs to (or otherwise selects) controllers 118 to control the cut-in speed of the milling drum 110 and initiates milling operations using the work machine 102. As the work machine 102 mills the working surface 116, pressure sensors 120 measure the pressure in one or more of the actuators 114 and send information indicating the pressure of the actuators to controllers 118. Controllers 118 control the rate at which the milling drum 110 descends into the working surface 116 based on this pressure.

[0066] For example, multiple pressure sensors 120 are arranged and configured to measure the pressure at the head and rod ends of one or more actuators 114. In one example, a first pressure sensor is configured to measure the pressure at the head end of one actuator 114, and a second pressure sensor 120 is configured to measure the pressure at the rod end of the actuator. Multiple controllers 118 calculate a measured differential pressure equal to the head pressure measured by the multiple pressure sensors 120 minus the rod pressure. The multiple controllers 118 compare the measured differential pressure of the actuators 114 with a threshold differential pressure and adjust the cut-in speed of the milling drum 110 based on this comparison, including, for example, decreasing the cut-in speed if the differential pressure is less than the threshold, or increasing the cut-in speed if the pressure is greater than the threshold.

[0067] The controllers (e.g., controllers 118) according to embodiments of this disclosure may include one or more controllers located on or away from the machinery. For example, the controllers according to embodiments of this disclosure may be included in or separate from the machinery. Embodiments of this disclosure may include multiple controllers that cooperate with each other to perform functions belonging to the controller(s). In embodiments, the controller(s) may be part of or included in an electronic control unit (ECU) of the working machinery.

[0068] The controllers, ECUs, etc., included in the examples of this disclosure can be configured to communicate with each other and with other parts of the working machinery using various public and / or proprietary standards and / or protocols via various wired or wireless communication technologies and components. Examples of transmission media and protocols for electronic communication between parts of the working machinery include Controller Area Network (CAN) protocol, Ethernet, Transmission Control Protocol / Internet Protocol (TCP / IP), IEEE 802.11 or Bluetooth, or other standard or proprietary transmission media and communication protocols.

[0069] In some instances, multiple controllers may be included within the ECU of the machinery. An electronic control unit (ECU) can be an embedded system that controls various aspects of the machinery's operation. Types of ECUs include electronic / engine control modules, powertrain control modules, transmission control modules, brake control modules, suspension control modules, and others. In the case of industrial, construction, and other heavy machinery, an exemplary ECU may also include a tool control module associated with one or more implements connected to and operable from the machinery. These electronic modules / units are communicatively connected and configured to send and receive data, sensor signals, or other digital and / or analog signals, and other information between the various ECUs of the machinery. Furthermore, functions belonging to controllers, ECUs, etc., may be distributed across multiple devices.

[0070] Multiple controllers (whether onboard and / or mechanically separated) may include software, hardware, and combinations of hardware and software configured to perform a number of functions belonging to the components of the disclosed examples. Such controllers according to embodiments of this disclosure may be analog controllers, digital controllers, or combined analog and digital controllers comprising multiple components. For example, multiple controllers may include integrated circuit boards or multiple ICBs, multiple printed circuit boards (PCBs), multiple processors, data storage devices, switches, relays, etc. Examples of processors may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuits.

[0071] In embodiments according to this disclosure, controllers, ECUs, and other electronic controls may include storage media for storing and / or retrieving data or other information, such as signals from sensors. Examples of non-volatile storage devices include magnetic hard disks, optical disks, floppy disks, flash memory, or electrically programmable memory (EPROM) or electrically erasable programmable memory (EEPROM). Examples of volatile storage devices include random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), and other forms of volatile storage devices. Data storage devices may be used to store program instructions for execution by, for example, processors of controllers.

[0072] Additionally, for example, the controllers, ECUs, and other electronic controls in embodiments of this disclosure may include additional digital and / or analog components, including transmitters, receivers, transceivers, and positioning systems, such as a Global Positioning System (GPS). In the examples, the controllers and / or ECUs may include GPS, from which they can send and receive data indicating the location of machinery or other components at the work site, and store and reference 2D or 3D maps of the work site.

[0073] As can be seen from the foregoing detailed embodiments, various features are combined in a single instance for the purpose of simplifying this disclosure. This method of disclosure should not be construed as reflecting an intention that the claimed instance requires more features than are clearly stated in each claim. Rather, as described in the following claims, the subject matter of the invention lies in fewer than all features in a single disclosed instance. Therefore, the following claims are hereby incorporated into the detailed embodiments, wherein each claim is considered an independent, separate instance.

[0074] Note that not all activities or elements described in the general description above are necessary, and a particular activity or device may not be required as part of a particular activity or device. Furthermore, one or more additional activities or elements may be performed in addition to those described. Moreover, the order in which the activities are listed is not necessarily the order in which they are performed. Additionally, the concept has been described with reference to specific examples. However, those skilled in the art will understand that various modifications and alterations can be made without departing from the scope of this disclosure as set forth in the following claims. Therefore, the specification and drawings are to be considered exemplary and not limiting, and all such modifications are intended to be included within the scope of this disclosure.

[0075] The benefits, other advantages, and solutions to problems have been described above with reference to specific examples. However, any benefits, advantages, solutions to problems, and any features(s) that may lead to or make any benefit, advantage, or solution occur or become more apparent should not be construed as key, necessary, or essential features of any or all claims. Furthermore, the specific examples disclosed above are merely illustrative, as the disclosed subject matter can be modified and practiced in different but equivalent ways, as will be apparent to those skilled in the art who have benefited from the teachings herein. The details of the constructions or designs shown herein are not intended to be limiting, except as set forth in the claims below. Therefore, it will be apparent that the specific examples disclosed above can be altered or modified, and all such changes are considered to be within the scope of the disclosed subject matter. Therefore, the protection sought herein is set forth in the claims below.

Claims

1. A type of operating machinery, comprising: frame; A milling drum, which is connected to the frame; A traction device, the traction device including an actuator configured to controllably raise and lower the frame relative to a working surface; A pressure sensor, operatively connected to the actuator and configured to measure the pressure of the actuator; as well as A controller, communicatively connected to the pressure sensor and configured to: Receive information indicating the pressure of the actuator from the pressure sensor; as well as The rate at which the milling drum descends into the working surface is controlled based on the pressure.

2. The operating machinery according to claim 1, wherein the controller is configured to: The pressure of the actuator is compared with the threshold pressure; and The rate at which the milling drum descends into the working surface is controlled based on the comparison.

3. The working machine according to claim 2, wherein when the controller determines that the pressure of the actuator is less than the threshold pressure, the controller is configured to reduce the rate at which the milling drum descends into the working surface.

4. The working machine according to claim 2, wherein when the controller determines that the pressure of the actuator is greater than the threshold pressure, the controller is configured to increase the rate at which the milling drum descends into the working surface.

5. The operating machinery according to claim 1, wherein the controller is configured to: At multiple times, information indicating multiple pressures of the actuator is received from the pressure sensor; The pressure change of the actuator is determined based on the multiple pressures of the actuator at the multiple time points; and The rate at which the milling drum descends into the working surface is controlled based on the pressure change.

6. The operating machinery according to claim 5, wherein the controller is configured to: The pressure change of the actuator is compared with the threshold pressure change; and The rate at which the milling drum descends into the working surface is controlled based on the comparison.

7. The working machine of claim 1, wherein the actuator comprises a hydraulic cylinder having a head end and a rod end, wherein the pressure sensor is a first pressure sensor configured to measure pressure at the head end, and further comprises a second pressure sensor configured to measure pressure at the rod end, and wherein the controller is configured to: Receive information indicating the head end pressure and the rod end pressure from the first pressure sensor and the second pressure sensor; The pressure difference of the actuator is calculated to be equal to the head end pressure minus the rod end pressure; and The rate at which the milling drum descends into the working surface is controlled based on the pressure difference.

8. The working machine according to claim 7, wherein when the controller determines that the pressure difference of the actuator is greater than a threshold pressure, the controller is configured to reduce the rate at which the milling drum descends into the working surface.

9. The operating machinery according to claim 1, wherein the controller is configured to: At multiple times, information indicating multiple pressures of the actuator is received from the pressure sensor; The pressure change rate of the actuator is determined based on the multiple pressures of the actuator at the multiple time points; and The rate at which the milling drum descends into the working surface is controlled based on the pressure change rate.

10. The operating machinery according to claim 9, wherein the controller is configured to: The pressure change rate of the actuator is compared with the threshold pressure change rate; and The rate at which the milling drum descends into the working surface is controlled based on the comparison.

11. The operating machinery according to claim 1, wherein the controller is configured to: Control the milling drum to descend into the working surface at a default rate; Receive the information indicating the pressure of the actuator from the pressure sensor; and The rate at which the milling drum descends into the working surface is changed based on the pressure.

12. The working machine of claim 1, wherein the default rate at which the milling drum descends into the working surface is based on the depth of cut.

13. The operating machinery according to claim 1, wherein the controller is configured to: Change the rate at which the milling drum descends into the working surface; Receive the information indicating the pressure of the actuator from the pressure sensor; and The milling drum is set to descend to a constant rate onto the working surface based on the pressure.

14. A method comprising: Information indicating the pressure of an actuator of a working machine is received from one or more pressure sensors. The working machine includes a milling drum connected to a frame and a traction device including the actuator, the actuator being configured to controllably raise and lower the frame relative to a working surface. as well as The rate at which the milling drum descends into the working surface is controlled based on the pressure.

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