System, apparatus, and method to perform leveling for borehole drills

A system, apparatus, and method for leveling a borehole or blasthole drilling machine, or portion thereof, provided over a drilling site can implement a ground contact detect phase or operation, a first coarse leveling phase or operation, a lowering phase or operation, and a fine leveling phase or operation. The phases or operations can be based on or responsive to signals from sensors of the drilling machine. The phases or operations can involve changing length of one or more of the jacks of the drilling machine when the drilling machine is positioned over the drilling site.

TECHNICAL FIELD

The present disclosure relates to automatic leveling, and more particularly to systems, apparatuses, and methods to automatically level borehole or blasthole drills positioned over a drill site for drilling.

BACKGROUND

For a drilling operation at a construction or mining site, such as a blasthole drilling operation, a drilling machine may generally follow an operating sequence involving: a propelling phase whereby the drilling machine is moved to a location where a hole is to be drilled; a leveling phase whereby the tracks, wheels, and/or wheel platforms of the drilling machine are raised off of the ground and the chassis of the drilling machine is leveled using jacks of the drilling machine, for instance, in order to drill a hole (e.g., vertical or inclined) at the desired location; a drilling phase whereby the drilling machine drills the hole; and a de-leveling phase whereby the drilling machine is returned to its state just prior to the leveling phase, including removing the drill bit from the hole and retracting the jacks such that the tracks, wheels, and/or wheel platforms are on the ground.

Some drilling machines may be fitted with an automatic leveling system. Such automatic leveling systems may avoid retracting or lowering one or more jacks (e.g., not lower any jacks) during the leveling phase in an effort to prevent loss of ground contact for the one or more jacks. Such systems may also use closed loop control using feedback from pitch and roll sensors of the drilling machine to control the jacks in an effort to achieve a desired level state. Filtering and a relatively slow response time of the pitch and roll sensors combined with relatively slow response time of the jacks may cause the automatic leveling system to overshoot the desired level state. Such tendency to overshoot, combined with the rule to not retract or lower one or more jacks, can result in continued oscillation of the leveling operation such that the jacks are extended more than is necessary (e.g., all jacks fully extended) or never achieve an acceptable level state.

Additionally, in a case where the drilling machine starts on very unlevel ground, the two-phase process of first lowering the jacks to ground and then leveling the drilling machine can mean that the jacks that were originally on the high side of the slope will be extended to the point where the tracks or wheels or wheel platforms on that side of the drilling machine will be higher than necessary off the ground. This can result in a less stable platform, as the jacks may be extended more than needed.

U.S. Pat. No. 4,679,489 (“the '489 patent”) describes an automatic leveling system for blast hole drills and the like. In particular, the '489 patent describes a dual automatic leveling system for a blast hole drill during raising and lowering which includes “fine” level sensors to detect an attitude with a fine level range and “course” level sensors to detect an attitude outside a course level range which is greater than that of the first. According to the '489 patent, the “fine” level sensors will be used to initially level the drilling platform, where if during such raising or lowering the platform becomes out of level by a certain amount the “coarse” level sensors will cause the raising or lowering process to stop and a re-leveling to +/−0.5° is effected before a raising or lowering is continued.

SUMMARY OF THE DISCLOSURE

In one aspect, an automatic leveling system for a blasthole or borehole drilling machine is disclosed. The system can comprise a plurality of jacks; a plurality of sensors; and a controller configured to receive signals from the sensors and control the jacks to automatically level a drill assembly of the drilling machine. The control includes a ground contact detect phase, followed by a first coarse leveling phase, followed by a lowering phase, and a fine leveling phase after the lowering phase.

In another aspect, a method for leveling a borehole drilling machine provided over a drilling site is disclosed. The method can comprise performing, under control of or using control circuitry, a contact surface detection operation to determine when each of a plurality of jacks positioned relative to the borehole drilling machine makes contact with a contact surface underlying the borehole drilling machine; performing, under control of or using the control circuitry, a first coarse leveling operation, after the contact surface detection operation; performing, under control of or using the control circuitry, a lowering operation, after the contact surface detection operation; and performing, under control of or using the control circuitry, a fine leveling operation, after the contact surface detection operation. The performing the contact surface detection operation, the performing the first coarse leveling operation, the performing the lowering operation, and the performing the fine leveling operation each include changing length of one or more of the jacks when the borehole drilling machine is positioned over the drilling site. The performing the fine leveling operation levels a chassis of the borehole drilling machine to a predetermined levelness range.

DETAILED DESCRIPTION

Embodiments of the disclosed subject matter involve automatic leveling, and more particularly systems, apparatuses, and methods to automatically level borehole or blasthole drills positioned over a drill site for drilling.

FIG.1is a diagrammatic end view of a drilling machine100according to embodiments of the disclosed subject matter. Generally, the drilling machine100can be used to drill a hole through material, such as rock. The hole may be referred to as a borehole or a blasthole, and may be filled with material (e.g., explosives) for the purpose of activating (e.g., detonating) the material within the hole.

The drilling machine100can be comprised of a chassis101, to which a traction system is coupled. The chassis101may refer to a drill assembly or a portion of a drill assembly of the drilling machine100. The traction system, according to embodiments of the disclosed subject matter, can be comprised of a set of tracks and/or a set of wheels or wheel platforms102. The traction system may be used to move the drilling machine100to and from a drill site.

The drilling machine100can also include a drill string104, which can be comprised of a drill bit105and other attachments; a deck bushing106, which may be to guide the drill string104; a rotary head107, which may be to turn the drill string104and apply downward pressure; and a tower108, which may be to attach the rotary head107to the chassis101.

The drilling machine100can also have, or have associated therewith, a plurality of jacks103, which may be referred to as leveling jacks103. Generally, the jacks103can be controlled, by control system200, which may be part of the drilling machine100, to make the drilling machine100, particularly the chassis101thereof, level prior to start of the drilling phase or operation. The jacks103may be individually and independently controlled, or, alternatively, controlled in pairs, for instance (e.g., front jacks103may be hydraulically coupled to equalize pressure). Jacks103may be positioned at corners or vertices of the chassis101, for instance, such as pairs of corners of the chassis101. For instance, in the case of a rectangular or square chassis101, jacks103can be respectively provided at the four corners of the chassis101.

The drilling machine100can also have a plurality of sensors, including one or a plurality of jack sensors203associated with each of the jacks103and an attitude sensor202. The jack sensors203can sense or detect information pertaining to the jacks103, such as position (e.g., amount of extension) and/or whether the jacks103have contacted a contact surface, such as ground, underlying the drilling machine100, and send such information to the control system200(interconnections between control system200and jack sensors203not shown inFIG.1andFIG.2. Discussed in more detail below, in certain phases or operations, the jack sensors203may constitute primary sensors and the attitude sensor202may constitute a secondary or auxiliary sensor.

As shown inFIG.3, the jack sensor203can provide signals to a processor or processing circuitry201of a control system200, according to embodiments of the disclosed subject matter. The processor or processing circuitry201, which may include or be able to access electronically readable memory, may be referred to herein as a controller or control circuitry. Optionally, some or all of the control system200may be referred to as a controller or control circuitry.

FIG.3, as an example, shows the jack sensors203in terms of contact surface detection sensors that determine when the jacks103have contacted the contact surface (e.g., ground). As a non-limiting example, jack sensors203in the form of contact surface detection sensors may be pressure sensors. For instance, jack sensors203may be hydraulic pressure sensors in the form of a switch in the jack103that sends a discrete (on/off) signal depending upon whether the hydraulic pressure in a given part of a jack cylinder exceeds a preset threshold or not.

Of course, jack sensors203, according to embodiments of the disclosed subject matter, may also be representative of additional jack sensors to sense position-related information (e.g., amount of extension, speed of extension and/or retraction, etc.) of the jacks103. Such jack sensors203can be provided within the jacks103, for instance, within jack actuators204thereof, and/or outside the jacks103. For instance, jack sensors203that can determine position of the jacks103and/or whether the jacks103contact the contact surface can be image sensors that capture images of the jacks103. To be clear, jack sensors203can represent sensors adapted to determine whether the jacks103have contacted the contact surface and/or sensors adapted to determine position-related information (e.g., amount of extension, speed of extension and/or retraction, etc.) of the jacks103.

The attitude sensor202, generally, can sense an attitude, for instance, roll and/or pitch, of the drilling machine100. According to one or more embodiments, the attitude sensor202can sense the roll and/or pitch of the chassis101. The attitude sensor202or information therefrom can determine a level state or levelness of the drilling machine100, particularly the chassis101thereof. As shown inFIG.3, signals from the attitude sensor202can be sent to the processor or processing circuitry201.

FIG.4shows an example of the attitude sensor202, according to embodiments of the disclosed subject matter, in the form of roll and pitch sensor circuitry400. The pitch and roll sensor circuitry400ofFIG.4can be adapted to measure pitch and roll of the drilling machine100, for instance, the chassis101thereof. The pitch and roll sensor circuitry400can include a pitch and roll sensor401, which may be or include one or more accelerometers, a heater402, temperature control circuitry403, an amplifier404, and a power supply405, which may be a low-noise power supply. The output of the roll and pitch sensor circuitry400may be provided to the processor or processing circuitry201.

As noted above, the control system200can have processor or processing circuitry201, which may be characterized or called a computing platform, that can processor signals from the attitude sensor202(or multiple attitude sensors202) and the jack sensors203. The processor or processing circuitry201can output control signals to control the jack actuators204based on the signals from the attitude sensor202and/or the jack sensors203. Such control may be characterized as closed-loop control. The processor or processing circuitry201can also control the jack actuators204(and hence the lengths of the jacks103) according to open-loop control, for instance, without use of signals from the attitude sensor202and/or the jack sensors203.

As noted above, the control system200can control the jacks103, by way of the jack actuators204, to make the drilling machine100, particularly the chassis101thereof, level prior to the start of the drilling phase or operation. Such leveling may be characterized as automatic, meaning that once the leveling process is initiated (e.g., responsive to a single input from an operator to initiate the leveling process), the process may proceed through the various phases or operations until the drilling machine100reaches a desired levelness target. Optionally, the jacks103can also be controlled during the drilling phase or operation to maintain the drilling machine100(e.g., the chassis101thereof) according to a particular level state or return the drilling machine100(e.g., the chassis101thereof) to the particular level state should the drilling machine100deviate outside of the particular level state. Such leveling may also be automatic, in this case, for instance, without the operator having to provide further inputs to maintain or correct the amount of levelness of the drilling machine100. According to one or more embodiments, the leveling control to level the chassis101may be independent of the control for the drilling operation.

According to one or more embodiments, the particular level state may be a range of degrees for the chassis101relative to a plane, such as horizontal or a plane perpendicular to a drilling direction or axis of the drill string104and drill bit105of the drilling machine100. For instance, the particular level state may be 0.1 degrees or less of horizontal or a plane perpendicular to a drilling direction or axis of the drill string104and drill bit105of the drilling machine100in a case where the drill string104and drill bit105are not exactly vertical. As another example, the particular level state may be less than 0.5 degrees of horizontal or a plane perpendicular to a drilling direction or axis of the drill string104and drill bit105of the drilling machine100in a case where the drill string104and drill bit105are not exactly vertical. Such leveling targets can be with respect to the x-axis and/or the y-axis.

Generally, the leveling prior to performing a drilling operation or phase can be performed when the drilling machine100is positioned over a drilling site and can include a ground contact detect phase or operation, a coarse leveling phase or operation, a lowering phase or operation, and a fine leveling phase or operation, using the control system200. The fine leveling phase or operation can orient the drilling machine100, particularly the chassis101or drilling assembly, for the drilling operation or phase. An option additional coarse leveling phase or operation may also be performed, for instance, between the lowering phase or operation and the fine leveling phase or operation. The foregoing phases or operations can involve changing length (e.g., lengthening or shortening) of one or more of the jacks103. It logically follows that such changing can be preceded by determining whether the length of the jacks103needs to be changed.

INDUSTRIAL APPLICABILITY

As noted above, embodiments of the present disclosure relate to automatic leveling, and more particularly systems, apparatuses, and methods to automatically level borehole or blasthole drills, which may be referred to herein as drilling machines, such as drilling machine100. Such automatic leveling can be performed once the drilling machine100is positioned over the desired drill hole location and prior to commencement of the drilling operation.

Hence, embodiments of the disclosed subject matter can provide an automatic leveling system and/or method utilizing a multi-step leveling process, wherein one or more of the steps may involve or implement machine learning operations. Leveling systems and/or methods according to embodiments of the disclosed subject matter can leverage a combination of closed loop control with so-call loose leveling targets and machine learning to overcome relatively highly filtered sensor signals and/or relatively slow jack103response times and minimize or avoid oscillations (e.g., overshoots) to achieve results in the fastest possible leveling time. Moreover, automatic leveling systems and/or methods according to embodiments of the disclosed subject matter may be used through the drilling phase, can adjust its responses automatically to the drilling machine on which it is installed, and can adapt to changing conditions of that particular drilling machine over time.

Automatic leveling systems and/or methods according to embodiments of the disclosed subject matter can bring a drilling machine, such as drilling machine100, to a predetermined level state, such as an ideal level state. An ideal level state may be within a predetermined tolerance, such as 0.1 degrees or less from horizontal (or a plane perpendicular to a drilling direction of the drilling machine100).

As noted above, leveling systems and methods according to embodiments of the disclosed subject matter can implement a ground detection step; an initial coarse leveling step; a lowering step; an optional coarse leveling step; and a fine leveling step to achieve and optionally maintain a state of level of the drilling machine100. According to one or more embodiments, the leveling system and/or method can implement or perform steps, operations, or phases consisting of the foregoing steps, operations, or phases to level the drilling machine100(with or without the optional coarse leveling step).

The leveling systems and/or methods according to embodiments of the disclosed subject matter can implement multi-point interpolated instructed continuous machine learning, which can allow the control system200to adapt its operation to particularities of the drilling machine100under control and/or changing conditions in the operation of the drilling machine100, such as fluctuations of ambient temperature, aging of components of the drilling machine100, and/or changing or differing characteristics of the underlying contact surface of the drilling machine100. In that leveling systems and/or methods according to embodiments of the disclosed subject matter can be used during the drilling operation, the control can be so as to actively compensate for ground sagging, jack sagging, and/or other situations that can cause the drilling machine100to become un-leveled during drilling.

FIG.5is a flow diagram of a method500according to embodiments of the disclosed subject matter. The method500can be performed by or under control of the control system200, particularly the processor or processing circuitry201thereof. According to one or more embodiments, the method500can be implemented by or according to computer-readable instructions stored on a non-transitory computer-readable storage medium that, when executed by a computer, such as processor or processing circuitry201, perform the method500.

The method500may begin with the initiation of a leveling operation. As noted above, the leveling operation may begin when the drilling machine100is positioned over the desired drill hole location (and prior to commencement of the drilling operation). As noted above, the method500may be performed in its entirety in response to a single input from an operator to initiate the method500, for instance, at a control interface (not shown) of or associated with the drilling machine100.

At S502the method500can implement a contact surface detection phase or operation. S502can include detection of whether the jacks103are in contact with a contact surface underlying drilling machine100. Such operation may also involve lowering or extending, i.e., changing a length of, one or more (e.g., all) of the jacks103, under control of the control system200, particularly the processor or processing circuitry201and the jack actuators204, depending upon whether or not the jacks103are initially determined to be contacting the contact surface. Such lowering can be until the control system200determines that the jacks103have reached the contact surface. Optionally, according to one or more embodiments, the jacks103may be lowered simultaneously, though the jacks103may not all contact the contact surface at the same time, for instance, because of different elevations of the contact surface and/or different speeds of lowering the different jacks103.

The lowering of the jacks103can raise the chassis101, for instance, such that the track/wheel platform(s) of the traction system102are raised off of the contact surface. Optionally, the track/wheel platform(s) of the traction system102can be raised so as to be out of contact with the contact surface.

The detection of whether the jacks103contact the contact surface can be performed using feedback, i.e., signals from the jack sensors203and/or the attitude sensor202. Such feedback may be characterized as closed-loop control. In the case of the attitude sensor202, the attitude sensor202can send pitch and roll signals corresponding to movement of the drilling machine100, for instance, the chassis101, to the processor or processing circuitry201. The processor or processing circuitry201can process the signals from the attitude sensor202to determine when each jack103contacts the contact surface. As an example, the detection of whether the jacks103contact the contact surface can be based on whether the height or level and/or levelness of the chassis101changes by a predetermined amount. For instance, the beginning of rising of a portion of the chassis101associated with one of the jacks103may cause the attitude sensor202to output signals indicative of the associated jack103contacting the contact surface (and hence causing the portion of the chassis101to rise).

Optionally, contact surface detection may be based on whether one or more of the jack sensors203has been previously found or is currently found to be unreliable (e.g., error state, failed, etc.). The jack sensors203, therefore, may, in one or more embodiments, constitute a primary contact surface detection system, and the attitude sensor202may constitute a secondary or auxiliary contact surface detection system. For instance, in a case where one or more of the jack sensors203is determined to have failed, signals from the attitude sensor202can still be used by the processor or processing circuitry201to determine when the jack or jacks103associated with the failed jack sensor(s)203contacts the contact surface. Hence, according to embodiments, in the absence of dedicated jack sensors203in the form of contact surface contact sensors203(e.g., failure of one or more jack sensors203) additional measurement and machine state information can be leveraged to determine contact surface contact of the jacks103. Such machine state information can include a previously known state of the jack103, a presumed state of the jack103, agreement or conflict with other sensors, previous control commands for the jack103and/or timing information regarding control of the jack103. On the other hand, if the jacks sensors203are deemed reliable (e.g., not determined to be failed), then the contact surface detection may be based on only the signals from the jack sensors203and not the attitude sensor202.

The method500may proceed at S504back to S502until contact with the contact surface has been determined for all of the jacks103. When all of the jacks103have been determined to have contacted the contact surface, for instance, using the control system200, the method can proceed to S506.FIG.6AandFIG.6Bmay be representative of a transition from initiation of the leveling operation (inFIG.6A) to a state where the jacks103are determined to be in contact with the contact surface300(FIG.6B, though noting that only one jack103is shown contacting the contact surface300).

Operation or phase S506of method500can involve a coarse leveling phase or operation at S506. Optionally, the coarse leveling phase or operation S506may be a first of two coarse leveling phases or operations.

Generally, the coarse leveling phase or operation S506can include changing length of one or more of the jacks103, under control of the control system200, for instance, so the drilling machine100, particularly the chassis101or drill assembly, is within a first leveling target. The first leveling target may be range of degrees for the chassis101relative to a predetermined plane, such as horizontal or a plane that is perpendicular to a drilling direction of the drill string104and drill bit105. Such first leveling target may be characterized as a loose leveling target, meaning that the leveling target is greater in range or tolerance than a range or tolerance of a leveling target associated with the fine leveling phase or operation S518(discussed in more detail below). As a non-limiting example, the first leveling target may be 0.5 degrees or less relative to horizontal or a plane perpendicular to the drilling direction of the drill string104and drill bit105. Such leveling target can be with respect to the x-axis and/or the y-axis.

The coarse leveling phase or operation S506can be characterized as a closed-loop feedback phase or operation, since the control of the level of the chassis101to the first leveling target can be based on signals from the attitude sensor202provided to the processor or processing circuitry201and the processor or processing circuitry201controlling the jack actuators204and hence the jacks103accordingly. Leveling the chassis101according to a so-called relatively loose leveling target can prevent the system from entering an oscillating state and therefore extending the jacks103by an unnecessary amount.FIG.6Cmay be representative of the drilling machine100, particularly showing the chassis101, at the end of the coarse leveling phase or operation S506.

The method500may proceed at S508back to S506until contact with the chassis101has been leveled, by control of the jacks103, to the first leveling target. Once the chassis101has been determined to be at or within the first leveling target, the method500can proceed to S510.

NotablyFIG.6Cshows an example of starting from a significantly un-level state at the end of the coarse leveling phase or operation S506can lead to excessive jack extension301. This can result in a less stable platform, as one or more of the jacks103may be extended more than needed, giving the drilling energy more leverage on the longer than necessary jacks103. To address this issue, embodiments of the disclosed subject matter can perform a lowering operation or phase at S510. Generally, the lowering phase or operation S510can involve changing length, i.e., shortening, of one or more of the jacks103to respective minimum lengths while maintaining contact between the jacks103and the underlying contact surface300. Optionally, such lowering of the jacks103may be such that the track/wheel platform(s)102of traction system remain out of contact with the contact surface300.

The lowering operation or phase at S510can be based on a determined speed of lowering the jacks103, as determined using signals from the jack sensors203and/or the attitude sensor202and processed by the processor or processing circuitry201, as well as an initial pitch angle of the drilling machine100, particularly the chassis101thereof, and a priori knowledge of geometry of the drilling machine100. The initial pitch angle may be with respect to the pitch angle of the drilling machine100prior to the contact surface detection phase or operation S502. Machine learning may be implemented, for instance, by the control system200, to determine the speed of lowering of each of the jacks103, which can be combined with the a priori knowledge of machine geometry of the drilling machine100as well as the initial pitch angle, to calculate the correct amounts of lowering to apply to the jacks103after the coarse leveling phase or operation S506. For instance, the processing may involve using the machine level before the coarse leveling relative to a measured distance between the jack103associated with a highest edge of the chassis101and a close tip of the corresponding track. If the calculated distance301between the track102and the ground plane300is greater than a predetermined threshold, the jack103can be lowered. The foregoing can allow the system to reduce the jack103extended length to a minimum, while still maintaining contact with the contact surface for all jacks103.

The method500may proceed at S512back to S510until all of the jacks103have been controlled, under control of the control system200, for instance, to their respective minimum lengths. Once all of the jacks103have been controlled to their minimum lengths, the method can proceed to either another coarse leveling phase or operation at S514or a fine leveling phase or operation at S518.

The coarse leveling phase or operation at S514, hence, may be an optional phase or operation, and may be performed, for instance, if during the lowering phase or operation S510the leveling state of the drilling machine100transitions from the leveling target of the coarse leveling phase or operation S506to outside this leveling target. For instance, speed differences between the jacks103during the lowering phase or operation S510may have caused the drilling machine100to be un-leveled outside the leveling target for the coarse leveling phase or operation S506. The coarse leveling phase or operation S514may then be performed, and may be the same as the coarse leveling phase or operation S506, perhaps with the exception of the starting point for this particular phase/operation. In this regard, the leveling target may be the same as in the coarse leveling phase or operation S506. Alternatively, the leveling target may be different, for instance, between the leveling target of the coarse leveling phase or operation S506and the leveling target for the fine leveling phase or operation S518(discussed in more detail below). For instance, the leveling target for the coarse leveling phase or operation S514may be 0.4 or less degrees from horizontal or a plane perpendicular to the drilling direction of the drilling machine100. As noted above, leveling the chassis101according to a so-called relatively loose leveling target can prevent the system from entering an oscillating state (i.e., overshooting) and therefore extending the jacks103by an unnecessary amount.

The method500may proceed at S516back to S514until contact with the chassis101has been leveled, by control of the jacks103, to the leveling target for the coarse leveling phase or operation S514. Once the chassis101has been determined to be at or within this leveling target, the method500can proceed to S518.

S518can represent a fine leveling phase or operation, and can involve leveling the drilling machine100, for instance, the chassis101thereof, to a leveling state or target that is more level than the leveling target(s) of the coarse leveling phase or operations S506, S514. For instance, the leveling target for the fine leveling phase or operation S518, which may be referred to herein as a second leveling target, may be 0.1 degrees or less relative to horizontal or a plane perpendicular to the drilling direction of the drilling machine100. Such fine leveling target can be with respect to the x-axis and/or the y-axis.

The fine leveling phase or operation S518may be performed according to open-loop control. This can mean that the control is performed without feedback from the attitude sensor202and/or the jack sensors203. Open-loop control can be implemented to overcome overshoot and resulting oscillations (i.e., overshoots) that could otherwise be induced by the relatively slow response time of the attitude sensor202and the jack sensors203, and the jacks103.

The open-loop control, which may be performed by the processor or processing circuitry201, may be according to multi-point interpolated instructed continuous machine learning. Such multi-point interpolated instructed continuous machine learning can be used to determine the amount of movement of each jack103to correct the state of level of the drilling machine100. Generally, multi-point interpolated instructed continuous machine learning can mean interpolation made on a discrete function for which the image value for multiple points are continuously learned and updated by the machine (i.e., processor201) itself, based on the constrained observation of results obtained upon actions taken in specific conditions. Put another way, the processing of the processor201(i.e., one or more algorithms) can learn what to do for a subset of reference conditions and interpolates for all conditions for which it has no specific knowledge. After each attempt to correct the state of level is executed, the control system200can measure performance and apply an immediate correction to the data point used in a multipoint list. Such control can prevent the system from diverging.

According to one or more embodiments, the fine leveling phase or operation S518can constrain movement of a determined highest corner of the drilling machine100(e.g., the chassis101) while the other corners are adjusted up or down to achieve the second leveling target. Such constrained control can involve preventing a determined highest jack103(and hence the highest corner of the chassis101) from being moved in either direction. Such constrained control can also involve no constraints for the other jacks103. According to one or more embodiments, the highest corner of the chassis101may correspond to the one of the jacks103that is extended the most relative to the other jacks103.

The method500may proceed at S520back to S518until the levelness of the drilling machine satisfies the second leveling target for the fine leveling phase or operation S518. Such target may reach the point of attempting to make micro-adjustments (e.g., within portions of a degree, such as 0.05 degrees), where the process may be considered complete when the tentative adjustments are within a certain value. The threshold value for ending the fine leveling phase or operation S518can be both configurable and dynamic. Generally, the level tolerance can be configurable, since the initial tolerance can be adjusted based on an operator's preferences regarding speed versus accuracy. And the level tolerance may be dynamic in that the tolerance can be automatically increased based on maximum time to achieve the target level, how much actual improvement is obtained on each adjustment, etc. The fine adjustment phase or operation S518can bring the drilling machine100to a state of level that is appropriate for drilling operations.

After achieving the second leveling target at the fine adjustment phase or operation S518, drilling can commence. The method500, however, can continuously monitor the levelness of the drilling machine100even during drilling operations and make adjustments to the level of the drilling machine100. Such control can be based on feedback from the jack sensors203and/or the attitude sensor202. Moreover, such control can maintain or return the levelness of the drilling machine100to within a predetermined leveling target, for instance, the second leveling target. Hence, as shown inFIG.5, the method500may return control to perform the fine adjustment phase or operation S518in the event that the levelness of the drilling machine100actually or is anticipated to deviate from the second leveling target. Likewise, in the event that the drilling machine100deviates more significantly, control may return to the coarse leveling phase or operation S514.

The continuously monitoring during drilling operations can apply corrections to maintain sufficient level if significant changes are observed. This phase can run continuously during the drilling phase to compensate for ground sagging, jack sagging, or other conditions that may result in the drilling machine100becoming un-level during the drilling process.