Background

[0001] This disclosure is related to the field of geophysical sensing devices such as seismic sensors (e.g., geophones, hydrophone or accelerometers) and/or autonomously operated sensor recording devices ("nodes") deployed in the soil proximate the ground surface for sensing physical parameters of geologic formations in the subsurface. More specifically, the disclosure relates to devices for automatically deploying geophysical sensors or sensor nodes in the ground.

[0002] Geophysical sensors are known in the art to be deployed in the ground above an area of the subsurface for which geophysical parameter measurements are to be made. Such parameter measurements include seismic signals, both subsurface originating and controlled source, surface reflection seismic signals, for example. Seismic sensors known in the art may include a sensor such as a geophone or accelerometer, multiple component geophones or accelerometers and/or hydrophones for measuring seismic energy originating in or reflected from acoustic impedance boundaries in the subsurface. Seismic sensors of the foregoing types may be wired together in multiple sensor "strings" or arrays, disposed in individual housings each having a spike or other ground contract device and pressed into the soil near the surface to make acoustic contact with the ground. In some implementations, a small hole may be dug or drilled to move the seismic sensor below layers of loosely consolidated soil so as to improve acoustic coupling between the sensor and the ground.

[0003] More recently, seismic and other geophysical sensors have been combined with autonomous recording nodes and/or wireless communication devices in individual housings. Some of such autonomous sensing and recording devices may be deployed in the ground by drilling or digging a hole to accommodate the housing, disposing the housing in the hole and in some cases covering the hole with the deployed housing therein. Manual deployment of such autonomous sensors and recording devices may be time consuming and labor intensive. Brief Description of the Drawings

[0004] FIG. 1 shows an example automatic sensor deployment apparatus that may be mounted on a vehicle or other transport device.

[0005] FIG. 2 shows a side, cutaway view of an example vehicle including a deployment apparatus according to one aspect.

[0006] FIG. 3 shows a top view of the vehicle and deployment apparatus of FIG. 2.

[0007] FIG. 4 shows another example embodiment of a deployment apparatus.

[0008] FIG. 5 shows an example embodiment of an insert for a staging unit.

Detailed Description

[0009] An example apparatus for automatically deploying geophysical sensors or sensor nodes in the ground is shown schematically in FIG. 1. The deployment apparatus 10 may be mounted to any type of vehicle (see FIGS. 2 and 3) suited for movement along the particular ground surface where geophysical sensors or nodes are to be implanted into the ground surface. The type of vehicle may be selected to suit the particular surface features of the ground surface where the geophysical sensors are to be deployed, e.g., a track drive vehicle for soft sand or mud, or rubber tire drive vehicles for more level, firm ground surfaces. The type of vehicle used in any particular embodiment is not intended to limit the scope of the present disclosure.

[0010] Sensors and/or sensor nodes (see FIG. 4) may be stored in the vehicle in a manner such that individual sensors or sensor nodes may be retrieved from the storage in the vehicle and moved to the deployment apparatus 10 for deployment in the ground surface, for example, one at a time. Non limiting examples of sensor nodes may include sensor nodes sold under the trademarks NRU 1C and NRU 3C, both of which are trademarks of Geophysical Technology, Inc., Bellaire, Texas. Other examples of sensor nodes may include, without limitation, devices such as described in U.S. Patent No. 8,614,928 issued to Kooper et al. and U.S. Patent No. 8,611,191 issued to Ray et al. Examples of individual sensors that may be deployed using an apparatus according to the present disclosure may be, for example and without limitation, ones such as shown in U.S. Patent No. 8,238,197 issued to Crice et al.

[0011] The deployment apparatus 10 may include a powered ram 12, which may be, for example an hydraulic ram. The diameter of the powered ram 12 may range from 0.025 inches to 3 inchesin some embodiments. The stroke length of the powered ram 12 for purposes of this description may be defined as the difference between the distance of the tip of the fully retracted ram to a fixed reference to the distance with the ram tip fully extended. To achieve sufficient ground penetration, this distance may be between 6 and 36 inches in some . A fixed part of the powered ram 12 (i.e., the ram cylinder in an hydraulic ram) may be mounted to the vehicle (FIGS. 2 and 3). A lower end of the powered ram 12, that is, the movable part, may include a ground-penetrating bit or spike 14 mounted thereon. The bit or spike 14 may be shaped to displace the soil when the powered ram 12 is extended so as to create a hole for insertion of a sensor or sensor node therein.

[0012] Power to operate the powered ram 12 may be provided by an hydraulic pump 40 if the powered ram is hydraulic. In other embodiments, the powered ram 12 may be, for example driven by a jackscrew rotated by a motor and a ball nut coupled to the bit or spike 14. In another embodiment, the powered ram 12 may comprise a sled that translates along an axis derived from alignment to the gravitational field of the Earth. The sled remains at a fixed distance from the chamber unit assembly 16.

[0013] A chamber unit assembly 16 may be disposed axially below the bit or spike 14 to guide the bit or spike 14. When the powered ram 12 is retracted, the bit or spike 14 may be positioned directly above a corresponding through bore 17 in the chamber unit assembly 16 that may assist in guiding the bit or spike 14 as the powered ram 12 is extended. In one example embodiment, the chamber unit assembly 16 (see FIG. 5) comprises a fitting that includes a flange 16A with and internal cylinder 16B. The diameter of the internal cylinder 16B may be between 2.5 and 5.5 inches. The internal diameter of the cylinder 16B should be approximately the same as the external diameter of the sensor or sensor node. The inner diameter of the cylinder 16B should provide an opening that allows a free range of 0.25 to 0.75 inches of movement from the inner diameter and the external diameter of the sensor or sensor node. Two flanges 16A may align along a common diameter that is approximately the same as the outer diameter of the cylinder 16B. The outer diameter of the flange 16A may be between 6 and 9 inches. A silicone grommet 16C that serves to collect the sensor or node may be disposed between adjacent flanges 16A and provides passage for the powered ram 12 and bit 14. A second set of flanges 16A having there between a corresponding silicone grommet 16C may be disposed between 3 and 6 inches from the center of the first grommet 16C. This arrangement provides the ability to align the powered ram 12 and the bit 14 along a center axis, while also providing for a "soft" stop for a sensor or node as it is disposed in the chamber unit assembly 16.

[0014] An example of the operation of the chamber unit assembly 16 may be described as follows. The sled comprising the hydraulic unit with the ram and bit ram remain at a fixed distance from each other. When the sled moves toward the ground, the chamber unit assembly 16 serves as a stop to the ground. Once the system detects the chamber unit 16 has touched the ground, the ram 12 is deployed by the extension of the hydraulic cylinder, and the bit 14 translates through chamber unit assembly 16, such that it is inserted into the ground commensurate with length of the sensor to be deployed. As the ram is returned to the cylinder, chamber unit 16 stays on the ground until a sensor or node is deposited into the silicone grommets 16C. At this time the bit returns to push the sensor or node into the ground using a low power mode.

[0015] In some embodiments, the powered ram 12 may be operated in at least two different power modes, wherein hydraulic power to operate the powered ram is supplied by a hydraulic pump 40 controlled by a control system 44 such as a microprocessor, programmable logic controller or any similar process control device. The control system 44 may be in signal communication with a linear position sensor 19 and a pressure transducer 21. The power mode may be controlled, for example by controlling hydraulic fluid pressure and flow rate. A high power mode may be enabled by operating the hydraulic pump 40 at a selected measured flow rate that and measured pressure. One skilled in the art will understand that the control system 44 may be adjusted to account for the type of ground condition by selecting time, pressure or flow rate thresholds appropriate to the type of ground. An example of a hydraulic power pack that may be used in some embodiments is commercially available from Hydra-Tech Pumps 167 Stock Street, Nesquehoning, PA 18240m such as model HT6DE. The foregoing pump can sustain a maximum flow of 4.5 gallons per minute with a maximum pressure of 1800 psi. The pump 40 and the powered ram 12 may be used for pressing the bit or spike 14 directly into the ground to create a hole for subsequently implanting a sensor or sensor node therein (FIG. 4). A low power mode similarly may be obtained by suitable control of fluid pressure and flow rate. The low power mode may be used to safely press-fit the sensor or sensor node (FIG. 4) into the previously prepared hole in the ground created by the bit or spike 14 when the powered ram 12 was operated in the high power mode. The powered ram 12 will then be retracted back out of the ground, passing up and through the chamber unit 16 back into its resting position above the chamber unit 16. The position sensor 19, which may be for example, a linear variable differential transformer may be provided to measure the length of the powered ram's 12 displacement so as not to force the sensor or sensor node into the ground surface in more than desired. In another embodiment, the control unit 44 may be programmed to respond to measurements from the position sensor 19 to a predetermined powered ram 12 displacement with an arbitrary zero setting. In one embodiment, the control unit 44 is programmed such that a positive displacement or extension of the powered ram 12 of 8 inches is equal to a measured ram extension of zero, or ground level. The pressure transducer, 21 may also be provided to measure the fluid pressure and thus the corresponding force exerted by the powered ram 12 to avoid applying excessive force to the sensor or sensor node in the low power mode.. The chamber unit assembly 16 may be provided with an opening (loading entrance) 18 axially displaced from the longitudinal axis of the powered ram 12 wherein a sensor or sensor node can be passed through by a loading mechanism. An example embodiment loading mechanism may comprise a crate with a latch, chute and collar. An example embodiment of a loading system will be explained below with reference to FIG. 4. With the control system 44 actuated, the loading system is selectively activated to release a sensor or node only in the event a hole in the ground surface has been successfully prepared, and the powered ram 12 has been returned to the retracted position. Thus in the event of a failure to create a sufficiently deep deployment hole, the control system 44 operates the powered ram 12 to return to the retracted position. The powered ram 12 may be automatically or manually reactivated depending upon the programming for the control system 44 chosen by the user. In one example embodiment, a spring loaded release pin or trigger curved plate, in a vertical position, and the chamber unit assembly 16 will accept and hold the sensor or sensor node that is passed into the chamber unit through bore 17. An example of such a mechanism may be similar in configuration as a spring loaded ammunition clip secured to a firing chamber of a pistol or rifle. In other embodiments, the sensor or sensor node may enter through a tube forming a "Y" merging with the path of the powered ram 12 just above the chamber unit assembly 16. One such embodiment will be further explained below with reference to FIG. 4.

[0017] The system may monitor and record and display for the operator, the geodetic position of the latest sensor or node deployment, the axiall orientation of the sensor or node with respect to vertical, the depth to which the node or sensor is deployed and the pressure used when inserting the sensor or node into the ground.

[0018] The chamber unit through bore 17 may, for example, have one or more D shaped springs (not shown) around the sides on a staging unit door 20, to hold the sensor or sensor node in place and vertically when the staging unit door 20 is closed. The staging unit door 20 may also have a D-shaped spring on it. In some embodiments, the chamber through bore 17 comprises sandwiched disks with diameter between 0.125 and 3 inches greater than the diameter of the sensor or node's widest point. In the top disk, or flange, see FIG 5, an elastomer with an opening that catches the sensor node, but for which is it easily released is described. For this specific example, an x-shape is introduced into the elastomer. Example elastomers include natural rubber, butyl rubber, Viton, nitrile butyl rubber and silicone rubber. [0019] In some embodiments, it may be desirable to disable the deployment of a subsequent sensor or node through the use of a mechanical system that comprises the staging unit door 20. The staging unit door 20 may comprise a sensor 20 A in signal communication with the control system 44. When the staging unit door 20 is closed, the control system 44 receives a signal from the sensor 20A indicative of the staging unit door 20 position, and in such case inhibits deployment or advancement of any additional sensor or node. In one example, the staging unit door 20 includes a hinged fastener to the chamber unit assembly 16. When the staging unit door 20 is open, the control system 44 receives a signal from the sensor 20A that the staging unit door 20 is open, and may operate the loading mechanism 18 such that a node or sensor can be advanced into the through bore 17. Such control may enabled by the control system 44 that locks sensor or node advancement when the door 20 is closed and unlocks sensor or node advancement when the door 20 is open. In an example embodiment, sensor or node deployment may be managed by the control system, e.g., as shown at 44, providing for a simplified mechanical design without the use of a staging unit door. In this example embodiment, the control system 44 may be programmed to stop advancement of any node or sensor into the through bore 17 in the absence of a successful hole punch. Absence of a successful hole punch may be determined in the control system 44 by examining recorded measurements of the linear position sensor 19 during a hole punch operation. A measurement of linear position indicative of failure of the powered ram 12 to extend to a distance corresponding to a fully punched hole may result in the control system 44 stopping advance of a sensor or node into the through bore 17 until which time as a successful hole punch is measured and recorded by the control system 44.

[0020] When a merging process is used the sensor or node will be allowed to drop or slide down into the chamber unit assembly 16 below the resting position of the powered ram 12. The D springs or other biasing devices, such as the sandwiched flanges (16C in FIG. 5) disposed around the interior wall of the chamber unit 16 may allow the sensor or node to drop into such location a selected amount and then be halted by friction between the D springs or other biasing device and the sensor or node. The sensor or node is thus held in a selected orientation and may be guided by the chamber through bore 17 as it is pushed through the chamber unit assembly 16 and into the previously created hole.

[0021] The chamber unit assembly 16 when closed will then allow the bit or spike 14, pushed by the powered ram 12, to pass (in a low power mode), top to bottom through the chamber unit assembly 16, and push a sensor or sensor node loaded into the chamber unit through bore 17 through the chamber unit assembly 16, out the bottom and into the prior pressed hole in the ground surface.

[0022] The chamber unit assembly 16, along with a caged lower unit 22, may guide the sensor or sensor node as it is pushed out of the chamber unit 16 and into the pilot hole.

[0023] A cap affixed to the upper end of each sensor or sensor node may also contain a wireless transceiver to perform instrument tests on the sensor or sensor node prior to being inserted into the ground. The cap may move with the sensor or sensor node and then return to the top where it swings out of the way for the ram to pass through when next commanded. An example of the foregoing communication system in a cap is described in U.S. Patent Application Publication No. 2011/0141850 filed by Scott et al.

[0024] The caged spacing unit 22 may be attached to the bottom of the chamber unit assembly 16 to keep the chamber unit assembly 16 elevated from the ground surface by a selected distance, for example about three to four inches (80 to 130 mm) to help keep the chamber unit assembly 16 clean and free of obstructions caused by lifting soil when the powered ram 12 is retracted.

[0025] The bottom of the caged spacing unit 22 may be formed into a circular opening that the bit 14 and sensor or sensor node can pass through. The caged spacing unit's 22 bottom presses on the ground, keeping the ground from pulling up when the powered ram is retracted out of the hole formed by the bit 14 when the ram 12 is operated to form a node or sensor hole. The caged spacing unit 22 may also be fitted to be able to be rotated on command to clear away and grass and small vegetation proximate the hole, so air movements will not allow such vegetation to sway and strike the sensor or node so as to create an acoustic vibration or noise in the sensor or node. [0026] A side mounted staging assembly unit (opening 18, door 20), may be attached to the side of the chamber unit assembly 16 at the side opening described above. The staging assembly unit (18, 20) may perform the following:

[0027] a) accept sensors or sensor nodes (either one at a time by hand, or a succession of the sensors or nodes conducted to the staging assembly unit (opening 18, door 20) by a conveyor system from a sensor or sensor node storage bin into the staging assembly unit. The sensor or sensor node is held in the staging assembly unit until the chamber unit 16 door is opened, allowing the sensor or sensor node to be loaded into the chamber unit 16. While a sensor or sensor node is in the staging assembly unit other sensors or nodes are excluded from entering the staging assembly unit. In embodiments having a "Y" shaped entry for the sensor or nodes a feeding mechanism may supply sensors or sensor nodes one at a time, and on command.

[0028] b) when the chamber unit door opens, the sensor or sensor node then in the staging unit is loaded into the chamber unit, the chamber unit door then closes and the conveyor system will then allow another sensor or node to enter the staging unit and be staged.

[0029] c) the staging unit and the conveyor system may be designed to allow for the attachment of a fully automated loading assembly, with a "bin" or "hopper" that holds a selected number of sensors or nodes, to be automatically placed in the automated loading assembly.

[0030] The deployment apparatus 10 may also have powered movement (that may operate manually or be automated) to position the deployment apparatus 10 in a vertical orientation for creation of the hole and deployment of the sensor or node, regardless of the terrain attitude.

[0031] FIGS. 2 and 3 show, respectively, a side cutaway view and a top view of an example vehicle 30 that may be used in some embodiments with the deployment apparatus 10 explained above. The vehicle may include a frame 34 mounted to the vehicle 30. The frame 34 may support the deployment apparatus 10. In the present example, the deployment apparatus 10 may be suspended at its upper end from a spherical joint swivel 32 at one end of an arm 33. The other end of the arm 33 may be coupled by a pivot 35 to the frame 34 to enable the arm 33 to be raised for vehicle movement and lowered for using the deployment apparatus 10. The deployment apparatus 10 may be coupled to two, angularly separated extension mechanisms 38. Each extension mechanism 38 may be, for example an hydraulic cylinder and ram as shown in FIG. 3. In other embodiments, the extension mechanisms 38 may each be, for example, a worm gear rotated by an electric or hydraulic motor (not shown in the figures). The arm 33 may be coupled at a position intermediate its two ends to a lifting mechanism 36, which in the present embodiment may be an hydraulic cylinder and ram. Operating pressure for the hydraulic cylinders (including, e.g., the powered ram 12 in FIG. 1) may be provided by an hydraulic pump 40 of any type known in the art.

[0032] The deployment apparatus 10 may include a tilt sensor 42 thereon. The tile sensor 42 may be any type known in the art, for example, an electrolytic bubble level sensor or a multiple axis accelerometer. The tilt sensor 42 may be in signal communication with a control unit 44. The control unit 44 may include a computer processor, such as a microcomputer, microcontroller, programmable logic controller, floating programmable gate array and the like. The control unit 44 may accept as input signals from the tilt sensor 42 and send control signals to the extension mechanisms 38 and the lifting mechanism 36 to automatically move the arm to the correct position for operation of the deployment mechanism 10 and to cause the deployment mechanism 10 to be in a substantially vertical orientation. Vertical orientation is only an example; any other selected orientation is within the scope of the present disclosure.

[0033] The control unit 44 may include a geodetic position signal receiver 44A, such as a

Global Navigation Satellite System (GNSS) receiver. The geodetic position signal receiver 44A may communicate the geodetic position of the vehicle 30, and correspondingly, the position of the deployment apparatus 10 so that the geodetic position of each deployed sensor or sensor node (FIG. 4) may be measured and recorded. In some embodiments, the geodetic position signal may be used to automatically operate the vehicle 30 such that each sensor or sensor node may be positioned at a predetermined geodetic position and/or in a preselected pattern or array. [0034] Another embodiment having a continuous sensor or node "feed" mechanism is shown schematically in FIG. 4. The vehicle 30 may include a staging ram 43 that can extend through a storage chamber 45 having a plurality of stacked sensor or nodes 46. When the staging ram 43 is extended, it pushes a lowermost one of the sensor or nodes 46 into a curved track 41. An end of the track 41 may be disposed substantially coaxially below the bit or spike 14 disposed at the end of the powered ram 12. The chamber unit 16 in the present example embodiment may be affixed to the end of the track 41 such that when a sensor or node 46 is moved into the track by the staging ram 43, the sensor or node falls by gravity into the chamber unit 16 for eventual insertion into the hole by the powered ram 12 substantially as explained above. When the staging ram 43 is retracted, another sensor or node 46 may fall by gravity into a position in front of the staging ram 43. In this way, a plurality of sensors or nodes may be stored for individual deployment by the deployment apparatus.

[0035] Some possible advantages of an automatic deployment apparatus according to the present disclosure may include one or more of the following.

[0036] The deployment apparatus mounting is flexible enough to mount onto the side of most any type of vehicle, for example, from small off-road utility vehicles or pickup trucks, or from the rear or through a "moon pool" opening in the floor of the cargo area of any such vehicle.

[0037] The deployment apparatus may be powered hydraulically (either from a dedicated power unit or connection to a vehicle hydraulic power takeout, for vehicles where available and with sufficient pressure and flow.

[0038] The deployment apparatus may be powered electro-mechanically, or purely mechanically with a small engine or by electric motors.

[0039] The deployment apparatus, if using an hydraulically powered ram may be assembled with or without pressure reservoirs (i.e., accumulator(s)) to speed up the hydraulic ram operation. [0040] The deployment apparatus may have computerized control of the orientation of the ram and chamber unit to enable creation of deployment holes in any selected orientation, e.g., vertical, irrespective of the attitude of the ground surface where the vehicle is located.

[0041] The deployment apparatus may be mounted on a frame that affixes to the vehicle, with powered slides, such that the deployment apparatus may be raised for traveling and lowered for node deployment operation.

[0042] The deployment apparatus may have control mechanism capable of operating the vehicle's brakes to lock when beginning hole punching and sensor or node deployment at any particular location.

[0043] The deployment apparatus power supply may be able to provide ram pressing action that can also contain vibrations, rotation, or high impacts, as well as directly pressing the spike or bit into the ground surface.

[0044] The deployment apparatus may be able to automatically move sensors or nodes from a mass storage "bin" or "hopper" (see FIG. 4) or other type of storage to the chamber unit assembly for deployment.

[0045] A sensor or node may be selected from the storage bin loaded into the chamber unit and then pressed into the hole created by the bit or spike immediately after it is withdrawn therefrom, and without moving the deployment apparatus. The sensor or node will then be urged into the hole by the powered ram.

[0046] The sensor or node may be configured to provide communications between the node being deployed and a computerized test and guidance unit in the vehicle.

[0047] The deployment apparatus may be provided with a computer or other processor that is programed to provide satellite and or other precision positioning and vehicle guidance to predetermined deployment geodetic locations.

[0048] The deployment apparatus and its controls may be fitted and programmed so to operate fully autonomously on a sensor or sensor node deployment program, with safety sensors and control. While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.