SURFACE DELAMINATION DETECTION / CORRECTION

Abstract

A milling machine can include a frame; a cutting rotor coupled to the frame, the cutting rotor configured to be lowered a selected distance into a first surface to define a depth of cut, the cutting rotor forming a cut surface; a sensor positioned to collect information regarding a quality of the cut surface behind the milling machine; and a controller coupled to the sensor to receive the information and configured to initiate an action to change the depth of cut in view of the information.

Description

TECHNICAL FIELD

The present disclosure generally relates to a milling machine. More particularly, the present disclosure relates to a system and method of controlling the depth of cut of the milling machine.

BACKGROUND

Milling machines can include machines such as cold planers. Cold planers are powered machines used to remove at least part of a surface of a paved area such as a road, bridge, or parking lot. Typically, cold planers include a frame, a power source, a milling assembly positioned below the frame, and a conveyor system. The milling assembly includes a cutting rotor having numerous cutting bits disposed thereon. As power from the power source is transferred to the milling assembly, this power is further transferred to the cutting rotor, thereby rotating the cutting rotor about its axis. As the rotor rotates, its cutting bits engage the hardened asphalt, concrete or other materials of an existing surface of a paved area, thereby removing layers of these existing structures. The spinning action of the cutting bits transfers these removed layers to the conveyor system which transports the removed material to a separate powered machine such as a haul truck for removal from a work site.

One problem that can occur while milling is delamination of the cut surface behind the milling machine. Delamination occurs when removing a specified depth of material and the cut is not deep enough to fully remove an existing layer from the substrate. This can be caused by previous overlay variances and existing surface conditions. This problem may cause raveling of material when exposed to the travel public which can initiate broken windshields, traction issues due to loose material, excessive debris in the work area, and require additional clean up efforts to meet requirements before a new surface is applied.

US 2021/0310202 discusses a system for automatically adjusting the height of a cutting rotor.

SUMMARY

In an example according to this disclosure, a milling machine can include a frame; a cutting rotor coupled to the frame, the cutting rotor configured to be lowered a selected distance into a first surface to define a depth of cut, the cutting rotor forming a cut surface; a sensor positioned to collect information regarding a quality of the cut surface behind the milling machine; and a controller coupled to the sensor to receive the information and configured to initiate an action to change the depth of cut in view of the information.

In one example, a system for controlling a milling machine can include a sensor positioned to collect information regarding a quality of a cut surface behind the milling machine after the milling machine has cut a first surface using a cutting rotor; and a controller coupled to the sensor to receive the information and configured to initiate an action to change a depth of cut of the cutting rotor in view of the information.

In one example, a method of controlling a milling machine can include lowering a cutting rotor of the milling machine to a selected depth of cut into a first surface; forming a cut surface in the first surface with the cutting rotor; determining a quality of the cut surface behind the milling machine, and a controller receiving the quality of the cut surface and initiating an action to change the depth of cut in view of the quality of the cut surface.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

FIG. 1 shows a side view of a milling machine, in accordance with one embodiment.

FIG. 2 shows a top perspective view of a cut surface, in accordance with one embodiment.

FIG. 3 shows a top perspective view of a cut surface, in accordance with one embodiment.

FIG. 4 shows a schematic side view of a cutting rotor cutting into a surface, in accordance with one embodiment.

FIG. 5 shows a schematic view of a control system, in accordance with one embodiment.

FIG. 6 shows a flowchart of a method of controlling a milling machine, in accordance with one embodiment.

DETAILED DESCRIPTION

FIG. 1 shows a side view of a milling machine 5, in accordance with one embodiment. In this example, the milling machine 5 is a cold planer 10. The cold planer 10 includes a frame 12, and a power source 14 connected to the frame 12. The power source 14 may be provided in any number of different forms including, but not limited to, Otto and Diesel cycle internal combustion engines, electric motors, hybrid engines and the like.

The frame 12 is supported by transportation devices 16 via lifting columns 18. The transportation devices 16 may be any kind of ground-engaging device that allows movement of the cold planer 10 in a forward direction over a ground surface 34, for example a paved road or a ground already processed by the cold planer 10. For example, in the shown embodiment, the transportation devices 16 are configured as track assemblies. The lifting columns 18 are configured to raise and lower the frame 12 relative to the transportation devices and the ground.

The cold planer 10 further includes a milling assembly 20 connected to the frame 12. The milling assembly 20 includes a drum housing 28 holding a rotatable cutting rotor 22 operatively connected to the power source 14. The cutting rotor 22 can be rotated about a drum axis extending in a direction perpendicular to the frame axis. As the rotatable cutting rotor 22 spins about its drum axis, cutting bits on the cutting rotor 22 can engage hardened materials, such as, for example, asphalt and concrete, of existing roadways, bridges, parking lots and the like. As the cutting bits engage such hardened materials, the cutting bits remove layers of these hardened materials. The spinning action of the rotatable drum 22 and its cutting bits then transfers the hardened materials to a first stage conveyor 26 via a discharge port 32 on the drum housing 28. The first stage conveyor 26 can be coupled to the frame 12 and located at or near the discharge port 32.

To lower the cutting rotor 22 into the surface, the lifting columns 18 are adjusted accordingly to allow the for the desired depth of cut. One or more sensors 50 can be located on the frame 12 to sense the position of the lifting columns 18 and can deliver that information to a controller 36 to determine the depth of cut of the cutting rotor 22. In another example, the sensors 50 can be attached to a side plate 29 of the machine to determine the depth of the cutting rotor 22.

The drum housing 28 includes front and rear walls, and a top cover positioned above the cutting rotor 22. Furthermore, the drum housing 28 includes side plates 29 on the left and right sides of the cutting rotor 22 with respect to a travel direction of the cold planer 10. The drum housing 28 is open toward the ground so that the cutting rotor 22 can engage in the ground from the drum housing 28. The drum housing includes the discharge port 32 in a front wall to discharge material to the first stage conveyor 26, which is located at or near the discharge port 32.

The cold planer 10 further includes an operator station or platform 30 including a control panel for inputting commands to a control system for controlling the cold planer 10, and a monitor 42 to display images and other operating information to the operator.

As noted above, delamination occurs when removing a specified depth of material and the cut is not deep enough to fully remove an existing layer from the substrate. In practice, a milling machine is set to a specified depth of cut that is dictated by a set of plans that a contractor bids on and works from after receiving the contract to proceed. For example, FIG. 2 shows a top perspective view of a cut surface 60 of the original surface 34 behind a milling machine when there is no delamination. Here, the cut surface 60 defines a relatively planar, even surface with a constant depth of cut into the surface 34. FIG. 3 shows a top perspective view of the cut surface 60 when delamination has occurred. Here, the depth of cut of the cutting rotor can produce the cut surface 60, but delamination has occurred and a deeper surface 62 has become exposed.

As noted, delamination can be caused by previous overlay variances and existing surface conditions. For example, delamination can occur when the removal of the prescribed depth of existing material meets the underlying layer or base due to inconsistency of the pavement depth when it was originally paved, over a length of time of use by the traveling public, not being cut deep enough as plans were drawn up to remove the layer, material losing adhesion due to break down of the tack oil, or the asphalt losing its cohesive structure which causes the delamination.

Delamination can cause several issues that can affect the IRI (international roughness index) of the roadway when measured, cause raveling of material when exposed to the travel public which can initiate broken windshields, cause traction issues due to loose material, cause excessive debris in the work area, require additional clean up efforts to meet requirements before new surface is applied, or result in improper adhesion of the new mat that will be laid down if the problem is not addressed early.

Regardless of the reason for delamination, adjustments need to be made in the milling process to correct the problem. Normally, the crew has to command the milling machine to cut deeper to resolve the delamination issue since raising the machine up in the cut could take them out of depth specification regulated in the plans.

Accordingly, the present system automatically detects the occurrence of delamination directly behind the machine and initializes an automatic correction by increasing depth with an adjustable depth value and/or through a message alert so the operator can adjust accordingly to reduce or eliminate the occurrence.

Accordingly, referring again also to FIG. 1, the present system includes one or more sensors 54 positioned to collect information regarding a quality of the cut surface 60 behind the milling machine 5 after the milling machine 5 has cut the original surface 34. In one example, the quality of the cut surface 60 is an objective determination of the degree of delamination that is occurring.

For example, the one or more sensors 54 can include one or more cameras or one or more laser distance sensors. The controller 36 can be coupled to the sensor 54 to receive the information regarding the quality of the cut surface 60 from the sensor 54 and then the controller 36 can be configured to initiate an action to change the depth of cut of the cutting rotor 22 in view of the quality information. Thus, the sensors 54 can detect the differences in the surfaces 60, 62 behind the milling machine 5 and the controller 36 can make any changes need as necessary.

For example, if the controller 36 determines from the information regarding the quality of the cut surface 60 that the depth of cut should be deeper into the surface 34 so as to prevent the delamination from occurring, the controller 36 can automatically adjust the depth of cut. For example, this can be done by sending a signal to lower the cutting rotor 22 a selected distance deeper into the surface 34.

In another example, if the controller 36 determines from the information regarding the quality of the cut surface 60 that the depth of cut should be deeper into the surface 34, the controller 36 can deliver a warning message to an operator to lower cutting rotor 22.

In this example, the information gathered by the sensor 54 regarding the quality of the cut surface 60 behind the milling machine 5 can include one or more objective parameters that indicate that delamination has occurred. For example, the information regarding the quality of the cut surface 60 behind the milling machine 5 can include information indicating that the cut surface has more than one depth such that the cut surface is not planar, as in FIG. 3 where the cut surface 60 has a different depth than the delaminated surface 62.

In one example, the controller 36 can include a set, predetermined maximum depth of cut. Accordingly, even if delamination is occurring, the controller 36 will not go any deeper with the cutting rotor 22.

FIG. 4 shows a schematic side view of the cutting rotor 22 cutting into a surface 34, in accordance with one embodiment. FIG. 4 shows how the surface 34 can be built upon a substrate 72 which can be any lower layer including a base or a previous laid asphalt layer. Here a layer 74 has been previously laid down onto the substrate 72 and the cutting rotor 22 of the milling machine has been instructed to cut to a depth of cut (D) into the layer 74, defining the cut surface 60. However, during the cutting process delamination has occurred resulting in the delaminated surface 62 appearing. The delamination can be detected by the sensor 54 due to the visual information or the difference in depths between the surface 60 and the surface 62. This information is received by the controller 36 which can then lower the depth of cut further into layer 74 in order to prevent the delamination. In one example, the depth of the cut can be lowered to reach an upper surface of the substrate 72. In other examples, the cutting rotor 22 can be lowered in stages, for example ¼″ at a time, until delamination does not appear.

FIG. 5 shows a schematic representation of the control system for controlling the milling machine, in accordance with one embodiment.

As discussed above, the control system can include the sensor 54 which can be positioned to collect information regarding a quality of a cut surface behind the milling machine after the milling machine has cut into the surface using a cutting rotor. The information from the sensor is received by the controller 36. The controller can be configured to determine from the information regarding the quality of the cut surface if any delamination of the cut surface is occurring and then to initiate an action to change the depth of cut of the cutting rotor in view of the information.

For example, if the controller 36 determines that the depth of cut should be deeper into the surface, the controller can cause an automatic adjustment 76 to change the depth of cut by sending a signal to lower the cutting rotor a selected distance into the surface.

In one example, if the controller 36 determines that the depth of cut should be deeper into the surface, the controller can deliver a warning message 78 to an operator to lower cutting rotor.

In general, the present system provides a surface delamination detection and correction system including detecting the delamination occurrence directly behind the machine, and then initiating an automatic correction by increasing depth with an adjustable depth value and/or through a message alert so the operator can adjust accordingly to reduce or eliminate the occurrence.

INDUSTRIAL APPLICABILITY

The present system is applicable to a milling machine such as a cold planer. As noted above, sometimes during a milling process, delamination of the cut surface can occur behind the milling machine.

FIG. 6 shows a method (200) of controlling a milling machine to identify and correct delamination during milling. The method (200) can include lowering a cutting rotor (210) of the milling machine to a selected depth of cut into a first surface and forming a cut surface in the first surface. The method further includes determining a quality of the cut surface (220) behind the milling machine after the milling machine has cut the first surface using the cutting rotor. As discussed, this can include using a sensor to deliver information to a controller to determine if delamination is occurring. The method further includes the controller receiving the information (230) and initiating an action to change the depth of cut in view of the information.

As discussed, the change of depth can be done automatically by the controller or the controller can send a message to the operator to perform a depth of cut change.

In summary, delamination can be caused by previous overlay variances and existing surface conditions. Adjustments need to be made in the milling process to correct the problem, since delamination can result in an uneven surface for potential traveling public, require additional cleanup measures, or cause improper adhesion of the new mat that will be laid down if the delamination problem is not addressed early.

Accordingly, the present system detects the occurrence of delamination directly behind the machine and initializes an automatic correction by increasing depth with an adjustable depth value and/or through a message alert so the operator can adjust accordingly to reduce or eliminate the occurrence.

The present idea is to provide a system for the milling machine to detect delamination through the use of cameras or other means and make any needed corrections based on the detection of the delamination scenario and make automatic corrections through the machine's grade and slope system automatically. If the correction is made it can be equal on both sides to maintain current grade conditions and at a calculated pace to eliminate a bump. In one option, the system can include a set point at which the milling machine would stop any additional depth changes (e.g., a preset maximum depth) to avoid cutting too deep per the specification.

The above detailed description is intended to be illustrative, and not restrictive. The scope of the disclosure should, therefore, be determined with references to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A milling machine comprising:

a frame;

a cutting rotor coupled to the frame, the cutting rotor configured to be lowered a selected distance into a first surface to define a depth of cut, the cutting rotor forming a cut surface;

a sensor positioned to collect information regarding a quality of the cut surface behind the milling machine; and

a controller coupled to the sensor to receive the information and configured to initiate an action to change the depth of cut in view of the information.

2. The milling machine of claim 1, wherein if the controller determines from the information regarding the quality of the cut surface that the depth of cut should be deeper into the first surface, the controller automatically adjusts the depth of cut.

3. The milling machine of claim 1, wherein if the controller determines from the information regarding the quality of the cut surface that the depth of cut should be deeper into the first surface, the controller delivers a warning message to an operator to lower the cutting rotor.

4. The milling machine of claim 1, wherein the sensor includes a camera.

5. The milling machine of claim 1, wherein sensor includes a laser distance sensor.

6. The milling machine of claim 1, wherein the information regarding the quality of the cut surface behind the milling machine includes one or more parameters that indicate that delamination has occurred.

7. The milling machine of claim 6, wherein the information regarding the quality of the cut surface behind the milling machine includes the cut surface having more than one depth such that the cut surface is not planar.

8. The milling machine of claim 7, wherein a portion of the cut surface has a depth as determined by the depth of cut and another portion of the cut surface has a deeper depth indicating delamination.

9. The milling machine of claim 1, wherein the controller has a predetermined maximum depth of cut.

10. The milling machine of claim 1, wherein the milling machine is a cold planer.

11. A system for controlling a milling machine comprising:

a sensor positioned to collect information regarding a quality of a cut surface behind the milling machine after the milling machine has cut a first surface using a cutting rotor; and

a controller coupled to the sensor to receive the information and configured to initiate an action to change a depth of cut of the cutting rotor in view of the information.

12. The system of claim 11, wherein if the controller determines from the information regarding the quality of the cut surface behind the milling machine that the depth of cut should be deeper into the first surface, the controller automatically adjusts the depth of cut.

13. The system of claim 11, wherein if the controller determines from the information regarding the quality of the cut surface behind the milling machine that the depth of cut should be deeper into the first surface, the controller delivers a warning message to an operator to lower the cutting rotor.

14. The system of claim 11, wherein the sensor includes a camera.

15. The system of claim 11, wherein sensor includes a laser distance sensor.

16. The system of claim 11, wherein the information regarding the quality of the cut surface behind the milling machine includes one or more parameters that indicate that delamination has occurred.

17. The system of claim 16, wherein the information regarding the quality of the cut surface behind the milling machine includes the cut surface having more than one depth such that the cut surface is not planar.

18. A method of controlling a milling machine, the method comprising:

lowering a cutting rotor of the milling machine to a selected depth of cut into a first surface;

forming a cut surface in the first surface with the cutting rotor;

determining a quality of the cut surface behind the milling machine; and

a controller receiving the quality of the cut surface and initiating an action to change the depth of cut in view of the quality of the cut surface.

19. The method of claim 18, wherein determining the quality includes using a sensor to analyze the cut surface behind the cutting machine to determine if delamination is occurring.

20. The method of claim 18, wherein initiating an action can include automatically changing the depth of cut or warning an operator of the milling machine.