Technology to adapt to instability of inclination angle in horizontal directional drilling

Abstract

The present invention discloses an inclination data processing system for a horizontal directional drilling system, which may include a detector, an offset and range calibration unit, an inclination speed limiter and a low-pass filter. The detector may include an accelerometer, which is configured to measure and output a raw inclination signal. The offset and range calibration unit may receive and process the raw inclination signal and output a calibrated inclination signal. The inclination speed limiter may receive the calibrated inclination signal. The inclination speed limiter is configured to set an upper limit and a lower limit of the inclination change speed. The inclination speed limiter may generate an inclination signal with limited speed change. The low-pass filter may receive a speed-limited inclination signal, and attenuate the received speed-limited inclination signal to above a selected cutoff frequency of the low-pass filter, and the low-pass filter is configured to output an adjusted inclination signal.

Description

Technical Field

[0001] The invention relates to a technology for adapting to the instability of inclination angle in horizontal directional drilling. Background Art

[0002] Utility lines for water, electricity, gas, telephone, and cable television are often laid underground for safety and aesthetic reasons. In many cases, underground utilities can be buried in trenches and then backfilled. While useful in new construction areas, burying utilities in trenches has certain disadvantages. In areas supporting existing construction, trenches can cause significant disruption to buildings or roads. In addition, digging trenches is likely to damage previously buried utilities, and building structures or roads disturbed by trench digging can rarely be restored to their original condition. In addition, open trenches can cause injuries to workers and passersby.

[0003] In order to overcome the above-mentioned shortcomings and other shortcomings that are not solved when adopting traditional trenching technology, a general technology for drilling horizontal underground holes has recently been developed. According to such a general horizontal drilling technology, also known as horizontal directional drilling (HDD) or non-excavation underground drilling technology, the drilling system is located on the surface and drills a hole underground at an inclination relative to the surface. The drilling fluid usually flows through the drill pipe, flows through the drilling tool, and flows back into the borehole to remove chips and dirt. After the drilling tool reaches the desired depth, the tool is guided along a substantially horizontal path to form a horizontal borehole. After the desired borehole length is obtained, the tool is guided upward to break through to the ground. The reamer is then connected to the drill pipe, and the drill pipe is pulled back into the borehole, thereby expanding the borehole to a larger diameter. A utility line or other conduit is usually connected to the reaming tool so that it can be dragged through the borehole together with the reamer.

[0004] Another technique associated with horizontal directional drilling, commonly referred to as push reaming, attaches a reamer to the drill pipe on the borehole entry side after the boring tool has exited on the borehole exit side. The reamer is then pushed through the borehole while the drill pipe being advanced from the borehole exit side is individually disconnected at the borehole exit location. This push reaming technique is sometimes used because it advantageously provides for recirculation of the drilling fluid. The level of direct operator interaction with the drill pipe, such as that required to disconnect the drill pipe at the borehole exit location, is much greater than that associated with conventional horizontal directional drilling techniques.

[0005] Horizontal directional drilling technology has evolved significantly over the past two decades. These developments involve both the drill rig and the position sensing and directional control components. There have been several types of position sensing and directional control systems used, with the walk-behind guidance system currently being the most accepted technology. Since the guidance / locator technology is quite different from the mechanical technology used to develop the drill rig, in most cases the same company has developed either the drill rig or the guidance system, but usually not both. As a result, there are now several walk-behind guidance system suppliers, each with a product that has unique features for use with a variety of drill rigs.

[0006] In the early days of horizontal directional drilling technology, it was recognized that it was possible to integrate remote electronic components that generate position information into the control of the drilling rig via radio signals or hard-wire transmission. Examples of this include U.S. Patents US4,646,277, US4,881,083 and British Patent GB 2175096, the entire contents of each of which are incorporated herein by reference. These systems are primarily configured as a drill-to-target system, in which the remote electronic components are placed at a location near the target point. The remote electronic components then cooperate with the drilling rig, particularly with the electronic components installed in the drill bit, and each individual component is integrated into the control system.

[0007] These systems have provided varying degrees of success in directing the cutting tool to a target point, but have not provided accurate and continuous position information regarding the cutting tool. As the cutting tool approaches various subsurface objects at various points in the borehole, close monitoring of the cutting tool's position is generally considered critical to the overall process. Therefore, systems that operate in a manner that directs the cutting tool to a target have proven to be less useful than systems in which the cutting tool's position is continuously monitored. These systems, currently referred to as walk-guide systems, have been developed to provide a continuous or quasi-continuous monitoring capability. Several patents have been issued disclosing various aspects of positioning systems for pedestrian guidance systems, including U.S. Patents 6,232,780, 6,008,651, 5,767,678, 5,880,680, 5,703,484, 5,425,179, 5,850,624, 5,711,381, 5,469,155, 5,363,926, and 5,165,490, the entire contents of each of which are incorporated herein by reference.

[0008] Other technologies that can provide information about the drill head's travel include gyroscopes, accelerometers, magnetometers, etc., used in various types of dead reckoning techniques or other techniques that involve the creation of an electromagnetic field that is sensed by the drill head's electronics. Data from such sensors is typically transmitted via so-called wires, where a physical wire conductor extends from the drill head back to the drill rig within the drill pipe, or via a wireless connection (e.g., Bluetooth wireless technology implementing short wavelength UHF radio waves). Summary of the invention

[0009] In the positioning profession of horizontal directional drilling, inclination data is key data for operators to steer the drill head. The inclination can be calculated in the transmitter based on the readings of the accelerometer. This calculation assumes that there are no external forces acting on the transmitter. However, during drilling, it cannot be assumed that there are no external forces (for example, those caused by hitting rocks or other hard objects). When moving and hitting hard objects, the acceleration caused by the impact may be indistinguishable from the acceleration of the position change. This sudden change in acceleration can cause the degree to be unstable. If the inclination data is not processed to resolve such anomalies, the inclination data may be unusable because it may jump all over the place. Using a low-pass filter, short spikes that appear in the reading can be ignored. However, this standard process does not always work in all cases, resulting in unstable displayed inclination data. This instability can lead to a loss of accuracy and / or productivity and, in some cases, can affect the safety of the drilling process.

[0010] The system can provide the operator with options regarding the calculation of inclination data based on the type of job being performed and / or the type of drilling rig being used. For example, a large job on a large machine may require high stability and accuracy because the larger housing and rods do not allow for rapid changes in inclination data. Conversely, a smaller job / machine may require a faster reaction to changes in inclination data and can tolerate more instability. In one embodiment, the raw inclination signal processing for the inclination data can be generated by a transmitter (e.g., associated with a detector) and transmitted from the transmitter (e.g., via Bluetooth transmission or another wireless connection) to a surface receiver.

[0011] Since drilling takes place entirely underground, there are physical limits on how quickly the inclination data can change. Therefore, extremely fast changes seen in the acceleration and inclination data are essentially "noise". If such a reading is truly accurate, then the result is likely to be a broken drill pipe. Therefore, the system can set upper and lower limits on the allowed rate of change of the inclination data for a readout (e.g., display or printout) from a previous measurement. Anything above or below the limits can be brought within the set limits. The user can select these limits before starting the job, for example through a Bluetooth connection between the transmitter and receiver.

[0012] The system allows the user to select an operating range of pitch data change rate for horizontal directional drilling operations and possibly select a pitch data change rate limit based on rotation / thrust conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following is a detailed description with reference to the accompanying drawings.

[0014] Figure 1 is an isometric diagram of a horizontal drilling system incorporating a component interface architecture according to an embodiment of the present invention;

[0015] Figure 2 For Figure 1 A schematic diagram of a walking locator system associated with a horizontal drilling system is shown;

[0016] Figure 3 is a schematic diagram of a standard inclination processing system associated with a horizontal drilling system;

[0017] Figure 4 A schematic diagram of an inclination processing data flow system of a horizontal drilling system combined with an inclination speed limiter according to an embodiment of the present invention;

[0018] Figure 5 A schematic diagram of a tilt processing data flow system of a horizontal drilling system with rotation-based speed limit value selection according to an embodiment of the present invention;

[0019] Figure 6 is an example of an inclination data graph, including accelerometer data, standard filtered inclination data, speed-constrained accelerometer data, and filtered speed-constrained inclination data;

[0020] Figure 7 is an example of an inclination data graph, including accelerometer data, standard filtered inclination data, speed-constrained accelerometer data, and filtered speed-constrained inclination data;

[0021] Figure 8 This is an example of an inclination data graph, the data comes from Figure 7 As shown in , including accelerometer data, standard filtered inclination data, speed limited accelerometer data, filtered speed limited inclination data, indicating the upper and lower limits of the inclination data. DETAILED DESCRIPTION

[0022] Various aspects of the present invention will be described more fully below with reference to the accompanying drawings, which form a part of this invention and show example features by way of illustration. However, these features may be embodied in many different forms and should not be construed as limited to the combinations described herein; on the contrary, these combinations are provided so that this invention will be thorough and complete and fully convey the scope.

[0023] Figure 1An overall horizontal directional drilling (HDD) system 10 according to an embodiment of the present invention is shown. Major components may include a drill rig 80, a mud system 30, and a pedestrian guidance system 800. The drill rig 80 may include a power system 85, a pipe handling system 20, a stake down system 70, and a strike alarm system 90. The pedestrian guidance system 800 may include an RF (i.e., radio frequency) unit 800a mounted on the drill rig 80, a locator 800b (e.g., an above-ground pedestrian locator unit), and a detector 800c (e.g., carried by a drill head (not labeled) of the drill rig 80). As described below, the RF unit 800a and / or the detector 800c may be considered part of the pedestrian guidance system 800 provided by a given pedestrian system manufacturer, or may not be included therein. Potential operators include a drill rig operator 40 and a locator operator 50.

[0024] Figure 2 Shown for Figure 1 80) of a pedestrian guidance system 800 for a drill rig 80 of the type shown. As described above, the pedestrian control and display system 900 may include an RF unit 800A (e.g., a remote unit with a display mounted on the drill rig 80), a locator 800B (e.g., a pedestrian locator), and a detector 800C. The RF unit 800C may include a processor 920A, a memory 930A, a communication or data link or interface 940A (e.g., in Figure 2 In one embodiment, the RF unit 800C may be an RF enabled controller. In one embodiment, the communication link 940C may be used for RF communication.

[0025] The locator 800B may include a processor 920B, a memory 930B, a communication or data link or interface 940B (e.g., Figure 2The probe 800C may include one or more motion sensors, such as one or more accelerometers 810, for measuring one or more of the tilt, yaw, or roll of the probe 800c, wherein the tilt measurement and display of the pedestrian control and display system 900 will be discussed in more detail later. The probe 800C may also include a processor 920C, a memory 930C, and an antenna 970C (e.g., a combination of components for processing, storing, and / or transmitting signals generated by one or more motion sensors). Antenna 970C may send signals to pedestrian locator 800B, and antenna 970B may receive signals from an underground transmitter (e.g., via underground antenna 970C). In one embodiment, the signals between antennas 970B, 970C may be communicated via Bluetooth or another short-range wireless communication mechanism.

[0026] The components of the pedestrian control and display system 900, as well as any other electrically or electronically connectable elements of the horizontal directional drilling system 10, can be at least partially communicatively connected (e.g., by wired or wireless communication) to automatically facilitate the above-described operations. The pedestrian control and display system 900 can also communicate with one or more system inputs (e.g., a touch screen, a keypad, a keyboard, a joystick, etc.) and / or one or more system outputs (e.g., a visual display or an audio or visual signal). Such system inputs and / or outputs can be associated with any of the drilling rig 80, the mud system 30, or the pedestrian guidance system 800.

[0027] In one embodiment, a given processor 920A, 920B, 920C provides processing functionality for a corresponding unit 800A, 800B, 800C and may include any number of processors, microcontrollers, circuits, field programmable gate arrays (FPGAs), or other processing systems, as well as resident or external memory for storing data, executable code, and other information accessed or generated by a given unit 800A, 800B, 800C. The processor 920A, 920B, 920C may execute one or more software programs embodied in a non-transitory computer-readable medium of the techniques described herein. The processor 920A, 920B, 920C is not limited by the materials from which it is formed or the processing mechanisms employed therein, and therefore, may be implemented by semiconductors and / or transistors (e.g., using electronic integrated circuit (IC) components), etc.

[0028] One example of a memory 930A, 930B, 930C may be a tangible computer-readable storage medium that provides storage functionality to store various data and / or program codes associated with the operation of a given unit 800A, 800B, 800C, such as software programs and / or code segments, or other data for instructing the processor 920A, 920B, 920C, and possibly other components of the pedestrian control and display system 900 and / or the entire horizontal directional drilling system 10 to perform the functions described herein. Thus, the memory 930A, 930B, 930C may store data, such as instruction programs for operating the system 900 (including its components), the horizontal directional drilling system 10, etc. It should be noted that although a single memory is described, various types and combinations of memories (e.g., tangible, non-transitory memories) may be used. The memory 930A, 930B, 930C may be integrated with the corresponding processor 920A, 920B, 920C, may include independent memories, or may be a combination of both.

[0029] Some examples of memory may include removable and non-removable memory components, such as random access memory (RAM), read-only memory (ROM), flash memory (e.g., secure digital (SD) memory card, mini SD memory card, and / or mini SD memory card), magnetic memory, optical memory, universal serial bus (USB) storage device, hard disk storage, external memory, removable (e.g., server and / or cloud) memory, etc. In particular embodiments, the memory 930A, 930B, 930C may include removable integrated circuit card (ICC) memory, such as memory provided by a subscriber identity module (SIM) card, a universal subscriber identity module (USIM) card, a universal integrated circuit card (UICC), etc.

[0030] The communication links or interfaces 940A, 940B are operably configured to communicate with components of the entire directional drilling system 10 and / or the pedestrian control and display system 900. For example, the communication interface can be configured to send and / or receive data for storage by the system 10, 900, etc. The communication links or interfaces 940A, 940B can also be communicatively connected to the corresponding processors 920A, 920B to facilitate data transfer between the components of the system 10, 900 and the given processor 920A, 920B. It should be noted that although the communication links or interfaces are described as controller components, one or more components of the communication links or interfaces can be implemented as external components that are communicatively connected to the system 10, 900 or its components through wired and / or wireless connections. The system 100, 300 or its components can also include and / or be connected to one or more input / output (I / O) devices (e.g., through a communication interface), such as a display and keyboard 950, a separate display, a separate keyboard, a mouse, a touch pad, a joystick, a touch screen, a keyboard, a microphone (e.g., for voice commands), etc.

[0031] The communication links or interfaces 940A, 940B and / or the processors 920A, 920B, 920C may be configured to communicate with a variety of different networks, such as a wide area cellular telephone network, such as a cellular network, a 3G cellular network, a 4G cellular network, a 5G cellular network, or a Global System for Mobile Communications (GSM) network, a wireless computer communication network, such as a WiFi network (e.g., a wireless local area network (WLAN) operating using the IEEE 802.11 network standard), a wireless ad hoc network, the Internet, a wide area network (WAN), a local area network (LAN), a personal area network (PAN) (e.g., a wireless personal area network (WPAN) operating using the IEEE 802.15 network standard), a public telephone network, an extranet, an intranet, and the like. However, the above list is provided only as an example and is not meant to limit the present invention. In addition, the communication links or interfaces 940A, 940B may be configured to communicate with a single network or multiple networks across different access points. In a particular embodiment, the communication link or interface can transmit information from the controller to an external device (e.g., a cell phone, a computer connected to a WiFi network, cloud storage, etc.). In another specific embodiment, the communication link or interface can receive information from an external device (e.g., a cell phone, a computer connected to a WiFi network, cloud storage, etc.).

[0032] Communication between components of the entire horizontal directional drilling system 10 and / or the pedestrian control and display system 900 can utilize any number of data link technologies. Examples of such technologies include those disclosed in U.S. Pat. No. 6,202,012, which is hereby incorporated by reference in its entirety. In one embodiment, the data link between components is implemented to comply with an industrial standard known as CAN. CAN is based on the ISO standard for serial data communications (ISO 11898).

[0033] Figure 3 A standard tilt processing system 1000 for use with a horizontal drilling system (e.g., horizontal directional drilling system 10) is illustrated. The standard tilt processing system 1000 may include an accelerometer 1010 (e.g., located at the detector 800c), an offset and range calibration unit 1020 (e.g., calibration hardware and / or software), and a low pass filter 1040. The signal generated by the accelerometer 1010 may be passed to the offset and range calibration unit 1020 and then passed through the low pass filter 1040 to produce fine tilt data suitable for output to a display (e.g., displayed as a percentage of tilt change over time) and / or for use in operation decisions (e.g., by a user or system controller). In one embodiment, the offset and range calibration unit 1020 and the low pass filter 1040 may be incorporated into the signal amplification and filtering unit 960B or the detector 800C. In one embodiment, the low pass filter 1040 passes signals with frequencies below a selected cutoff frequency and attenuates signals with frequencies above the cutoff frequency.

[0034] Figure 4 A tilt processing system 1100 for use with a horizontal drilling system (e.g., horizontal directional drilling system 10) according to an example embodiment of the present invention is shown. The tilt processing system 1100 may include an accelerometer 1110 (e.g., located at the probe 800c), an offset and range calibration unit 1120 (e.g., programmable calibration hardware and / or software), a tilt velocity limiter 1130, and a low pass filter 1140, which are connected to each other in electronic communication (e.g., wired or wireless) or in other ways. In one embodiment, the signal generated by the accelerometer 1110 can be passed to the offset and range calibration unit 1120, and then passed through the tilt velocity limiter 1130 and the low pass filter 1140, thereby generating an adjusted output of the tilt angle (e.g., displayed as a percentage of tilt change over time). In one embodiment, the offset and range calibration unit 1120 can receive and process the raw tilt signal (e.g., from the accelerometer / probe) and output a calibrated tilt signal. In one embodiment, the low pass filter 1140 may receive the speed-variation-limited tilt angle signal and attenuate the received speed-variation-limited tilt angle signal above a selected cutoff frequency of the low pass filter 1140 .

[0035] In one embodiment, the offset and range calibration unit 1120, the inclination rate limiter 1130, and the low pass filter 1140 are located above the ground (e.g., in the locator 800B, sending the "raw" accelerometer signal on the ground via Bluetooth or other wireless communication). In one embodiment, the offset and range calibration unit 1120 (e.g., calibration hardware and / or software), the inclination rate limiter 1130, and the low pass filter 1140 can be incorporated into the signal amplification and filtering unit 960B as part of the walking locator 800B. In another embodiment, the offset and range calibration unit 1120, the inclination rate limiter 1130, and the low pass filter 1140 can be located in the detector 800c, and the generated inclination output is sent to, for example, a ground display (e.g., 950A, 950B).

[0036] The inclination speed limiter 1130 can be in the form of software and / or a processing unit (e.g., hardware). The inclination speed limiter 1130 can set an upper limit on the inclination change speed and a lower limit on the inclination change speed, thereby creating a window or range of allowable inclination change speeds. A signal transmitter in the form of the inclination speed limiter 1130 can indicate that the next inclination reading displayed to the user is within the window (i.e., set range) of the previous inclination measurement. If the measured value is outside the window, it can be adjusted to within the window. This inclination adjustment performed by the inclination speed limiter 1130 can produce more stable inclination readings during operation. For example, the adjusted inclination data can be output to the display 950 (e.g., displayed to the system user) and / or used by the processor 920 (e.g., for controlling the operation of the HDD system).

[0037] In one embodiment, the pitch change rate limit can be based on the type of job being performed (e.g., the diameter of the component being transferred by the HDD system) and / or the type of drill bit being used. In one embodiment, the pitch change rate limit (e.g., the pitch change rate range) can be defined based on the maximum pitch change rate between the upper and lower pitch change rate limits. For example, large jobs on large machines require high stability and precision because the larger housings and rods generally do not allow for rapid changes in pitch, and typically require a tighter pitch change rate range (e.g., a pitch change rate range of 2-5% / second (sec) for larger rigs, or a pitch change rate range of 1% / sec for the largest rigs and / or more stringent requirements (e.g., sewer pipes)). Conversely, smaller jobs / machines typically require faster reactions to pitch changes and can tolerate more instability, thereby allowing a wider pitch change rate range (e.g., a pitch change rate range of 5-10% / sec). In one embodiment, the user can select the pitch speed range to be implemented. In one embodiment, a user may select a pitch change rate range using locator 800B, RF unit 800A, or another ground-based wireless device to communicate desired pitch change parameters to detector 800C.

[0038] Figure 5 A pitch processing system 1200 for use with a horizontal drilling system (e.g., horizontal directional drilling system 10) is shown according to an example embodiment of the present invention. The pitch processing system 1200 is similar in function and components to the pitch processing system 1100, except as described below. Therefore, similarly numbered components (e.g., accelerometers 1110 and 1210) can be expected to be constructed and operate in a similar manner. The pitch processing system 1200 can include an accelerometer 1210 (e.g., located at the probe 800c), an offset and range calibration unit 1220 (e.g., programmable calibration hardware and / or software), a "slow" pitch velocity limiter 1230A, a "fast" pitch velocity limiter 1230B, and a low pass filter 1240; as well as a roll sensor 1250 (i.e., integrated in the probe 800C) and a rotation detection unit 1260 (e.g., in the form of software and / or a programmable detection unit), in electronic communication (e.g., wired or wireless) with each other. In one embodiment, the offset and range calibration unit 1220 (e.g., calibration hardware and / or software), the "slow" pitch rate limiter 1230A, the "fast" pitch rate limiter 1230B, and the low pass filter 1240 may be incorporated into the signal amplification and filtering unit 960B.

[0039] The pitch processing system 1200 may allow for rotation-based speed limit detection. Based on the offset and range calibration 1220, it may be determined whether to use the "slow" pitch speed limiter 1230A when the drill 80 is rotating its associated drill bit (not labeled) or to use the "fast" pitch speed limiter 1230B for when the drill 80 is advancing its associated drill bit (not labeled). Whether rotation or advancement is occurring is determined by the roll sensor 1250 and the rotation detection unit 1260. The rotation detection unit 1260 may provide a signal to the limiter switch 1270 to activate the appropriate one of the "slow" pitch speed limiter 1230A or the "fast" pitch speed limiter 1230B (e.g., connecting the selected one to the low pass filter 1240). In one embodiment, the "slow" pitch speed limiter 1230A may be more stable, but its response to pitch changes may be relatively slow. Thus, the "slow" pitch speed limiter 1230A may be used when the drill bit is rotating and sudden pitch changes are not expected. In one embodiment, the "fast" pitch rate limiter 1230B is configured to provide a faster response to any changes in pitch angle, and faster changes in pitch angle are most likely to occur during propulsion mode. In one embodiment, when the "slow" pitch rate limiter 1230A and the "fast" pitch rate limiter 1230B are enabled, both can be operated in tandem, with only one of the two resulting signals being sent (e.g., a "slow" associated signal when rotating or a "fast" associated signal when pushing). In this embodiment, given the limitations of the data transmission bandwidth, only one signal is sent / transmitted at a time.

[0040] Figure 6 Raw accelerometer data, standard inclination data (filtered with a low pass filter), speed limit accelerometer data, and a comparison graph of speed limit and filtered inclination data (percent change in inclination over time, in seconds) are provided, the latter being displayed to the user. Figure 6 As shown, a close-up view (e.g., a five second window taken at a generally steady-state interval) can be used to display fluctuations in acceleration and the significant effects of using speed limits and / or low-pass filtering. As can be seen, standard inclination data, speed-limited accelerometer data, and speed-limited and filtered inclination data can provide progressively more refined levels of data in sequence. The speed-limited and filtered inclination data, which is the best data set in terms of limiting the "noise" from the accelerometer data, can be selected for output for user viewing (e.g., via display 950) and / or for implementing process control (e.g., by processor 920).

[0041] Figure 7Raw accelerometer data, standard inclination data (filtered with a low pass filter), speed-limited accelerometer data, and a comparison graph of speed-limited and filtered inclination data (percent change in inclination over time, in seconds) are provided. The change limit is 2% / second. Figure 7 A view showing the results of progressing from a starting position to a substantially steady state inclination level (e.g., moving to a desired depth and then substantially maintaining that depth) forms a slope graph until a near steady state is reached (e.g., after approximately 8 seconds). Figure 7 As shown, implementing a speed limit does not affect the actual ("raw") tilt change (e.g., accelerometer) measurement. That is, it is contemplated that the tilt processing system 1100, 1200 first measures the sensed (e.g., "raw") tilt change using the accelerometer 1110, 1210, which can then be processed (e.g., using a speed limit and a low-pass filter) to produce a refined tilt change output for use.

[0042] Figure 8 Provided from Figure 7 Comparison of the 4-6 second window obtained from the graph (percent change in inclination over time, in seconds). Figure 8 Also shown are the raw accelerometer data, standard inclination data (filtered with a low pass filter), speed-limited accelerometer data, speed-limited and filtered inclination data, with inclination changes limited to 2% / second. Figure 7 different, Figure 8 The upper and lower speed limits are further shown. Figure 7 Likewise, implementing a speed limit does not affect the actual ("raw") tilt change (eg, accelerometer) measurements.

[0043] When the transmitter is not underground, the system 1100, 1200 that limits the rate of change of the inclination angle may cause an obstruction. When the system 1100, 1200 is demonstrated above ground (e.g., at a trade show), the transmitter may encounter impossible underground readings. For example, the inclination angle may change suddenly from 0% to 40%. Under normal circumstances (i.e., underground), the system 1100, 1200 can limit the change over time, so it can slowly climb (e.g., according to the selected limit) instead of going to 40 immediately. Although such a scenario is unlikely to occur underground without a mechanical failure, such slow changes above ground can create a perception among customers and potential customers that the system 1100, 1200 and its associated transmitter are "slow." To address this issue, once the system 1100, 1200 detects a large jump in the inclination angle that exceeds this threshold limit of x% (e.g., 10%) and remains in the same direction for a specific period of time (1-2 seconds), it determines that the jump is an actual change in the inclination angle, rather than being caused by an object that produces a spike (e.g., an underground obstacle), and it can change the inclination angle change rate window size to allow for a faster rate of change. Once the rate of change of the tilt angle is below a threshold limit of x% (eg, 10%), it can make the window size smaller and slowly converge to the final tilt angle position.

[0044] Although the subject matter has been described in language specific to structural features and / or methodological acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. An inclination data processing system for a horizontal directional drilling system, the inclination data processing system comprising: The detector includes an accelerometer, wherein the accelerometer is used to measure and output a raw tilt signal; an offset and range calibration unit, for receiving and preliminarily processing a raw tilt signal, the offset and range calibration unit being configured to output a calibrated tilt signal; a pitch speed limiter, configured to receive the calibrated pitch signal output by the offset and range calibration unit, the pitch speed limiter being configured to set an upper limit of the pitch change speed and a lower limit of the pitch change speed, the pitch speed limiter being configured to generate a pitch signal with limited speed change, the pitch speed limiter comprising at least one of software or a processing unit; A low-pass filter is used to receive the speed-limited inclination signal output by the inclination speed limiter, the low-pass filter is configured to attenuate the received speed-limited inclination signal to above a selected cutoff frequency of the low-pass filter, and the low-pass filter is configured to output the speed-limited and filtered inclination signal, which can be used to display to a user or control at least one of the operations of the horizontal directional drilling system.

2. The inclination data processing system according to claim 1, characterized in that: The detector is implemented as an underground unit and the offset and range calibration unit, pitch velocity limiter and low pass filter are integrated into the surface locator unit.

3. The inclination data processing system according to claim 1, characterized in that: The detector is operated as an underground unit, and the offset and range calibration unit, inclination velocity limiter and low pass filter are integrated into the detector.

4. The inclination data processing system according to claim 1, characterized in that: A surface communication unit is included, the surface communication unit being configured to wirelessly communicate a maximum rate of change of inclination to the detector, the maximum rate of change of inclination being selected by a system user.

5. The inclination data processing system according to claim 1, characterized in that: The upper and lower inclination change speed limits are selected based on at least one of the size of the horizontal directional drilling system or the type of drilling operation being performed.

6. The inclination data processing system according to claim 5, characterized in that: For drilling conditions that can tolerate a greater degree of inclination instability, the maximum inclination change rate between the inclination change rate upper limit and the inclination change rate lower limit is selected to be 5-10% / second.

7. The inclination data processing system according to claim 5, characterized in that: For drilling situations requiring higher stability of the inclination angle, the maximum inclination angle change speed between the inclination angle change speed upper limit and the inclination angle change speed lower limit is selected to be 5% / second or less.

8. The inclination data processing system according to claim 1, characterized in that: The pitch speed limiter is a first pitch speed limiter configured to be used when the horizontal directional drilling system is in a propulsion mode.

9. The inclination data processing system according to claim 8, characterized in that: Also included is a second pitch speed limiter configured to be used when the horizontal directional drilling system is in a rotation mode.

10. The inclination data processing system according to claim 9, characterized in that: Also included is a rolling sensor and a rotation detection unit, both of which are collectively configured to determine which of the first tilt rate limiter and the second tilt rate limiter is selectively activated.

11. The inclination data processing system according to claim 1, characterized in that: The system is configured to, upon determining a large change in inclination exceeding a threshold limit in the same direction within a selected time, allow a faster rate of change in inclination until the rate of change in inclination is below the threshold limit.

12. An inclination data processing system for a horizontal directional drilling system, the inclination data processing system comprising: an offset and range calibration unit for receiving and preliminarily processing a raw inclination signal received from an accelerometer of the detector, the offset and range calibration unit being configured to output a calibrated inclination signal; a tilt speed limiter, connected in communication with the offset and range calibration unit, the tilt speed limiter being configured to receive a calibrated tilt signal output by the offset and range calibration unit, the tilt speed limiter being configured to set an upper limit of a tilt change speed and a lower limit of a tilt change speed, the tilt speed limiter being configured to generate a tilt signal with a speed change limited, the tilt speed limiter comprising at least one of software or a processing unit; A low-pass filter is communicatively connected to the inclination speed limiter, the low-pass filter is configured to receive the inclination signal with limited speed change output by the inclination speed limiter, the low-pass filter is configured to attenuate the received inclination signal with limited speed change to above a selected cutoff frequency of the low-pass filter, and the low-pass filter is configured to output the speed-limited and filtered inclination signal, which can be used to display to a user or control at least one of the operations of the horizontal directional drilling system.

13. The inclination data processing system according to claim 12, characterized in that: The offset and range calibration unit, pitch rate limiter and low pass filter are incorporated into one of the surface locator unit or the probe.

14. The inclination data processing system according to claim 12, characterized in that: The upper and lower inclination change speed limits are selected based on at least one of the size of the horizontal directional drilling system or the type of drilling operation being performed.

15. The inclination data processing system according to claim 14, characterized in that: For drilling conditions that can tolerate a greater degree of inclination instability, the maximum inclination change rate between the inclination change rate upper limit and the inclination change rate lower limit is selected to be 5-10% / second.

16. The inclination data processing system according to claim 15, characterized in that: For drilling situations requiring higher stability of the inclination angle, the maximum inclination angle change speed between the inclination angle change speed upper limit and the inclination angle change speed lower limit is selected to be 5% / second or less.

17. The inclination data processing system according to claim 12, characterized in that: The pitch speed limiter is a first pitch speed limiter configured to be used when the horizontal directional drilling system is in a propulsion mode.

18. The inclination data processing system according to claim 17, characterized in that: Also included is a second pitch speed limiter configured to be used when the horizontal directional drilling system is in a rotation mode.

19. The inclination data processing system according to claim 18, characterized in that: Also included is a rolling sensor and a rotation detection unit, both of which are collectively configured to determine which of the first tilt rate limiter and the second tilt rate limiter is selectively activated.

20. The inclination data processing system according to claim 12, characterized in that: The system is configured to, upon determining a large change in inclination exceeding a threshold limit in the same direction within a selected time, allow a faster rate of change in inclination until the rate of change in inclination is below the threshold limit.

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