Surveying pole with offset electronic ranging unit and method implemented in surveying pole

Abstract

The invention relates to a surveying pole with an offset electronic ranging unit and a method implemented in the surveying pole. The surveying and mapping pole comprises a pole device which extends along a longitudinal axis; a target disposed inside the rod device; a top unit mounted on a rod arrangement extending along the axis and comprising: a positioning device; an electronic ranging (EDM) unit configured to determine a distance to the target and arranged offset from the axis such that at least a portion of an optical path between the EDM unit and the target does not coincide with the axis within the top unit; optical means adapted to redirect the light path such that the light path maps the rod within the rod means parallel to the axis; and a processor configured to determine a length of the rod device based on the distance determined by the EDM unit.

Description

Technical Field

[0001] The present invention relates to a surveying rod, a method implemented in the surveying rod, and a top unit for the surveying rod. More specifically, the present invention relates to determining the length of the rod device of the surveying rod. Background Art

[0002] Surveying involves determining the three-dimensional position of points to map and create a model of the terrain or structure being surveyed. For this purpose, a surveying rod with a target and / or other surveying equipment such as a GNSS (Global Navigation Satellite System) antenna can be used. In use, the surveying rod is in contact with the measurement point. A surveying rod with a target is typically used in conjunction with a geodetic instrument (such as a geodetic scanner, theodolite or total station) to determine the distance and angle between the measurement point and the known position of the geodetic instrument. A surveying rod with a GNSS antenna can obtain its own position from the signals received from the satellites of the GNSS system. Thus, the position of the target and / or GNSS antenna is obtained. To determine the position of the measurement point, it is necessary to know the height of the target / antenna above the measurement point. For this purpose, an accurate measurement of the length of the surveying rod is required. At the same time, it is always desirable to improve the handling convenience of the surveying rod during operation and transportation, especially by minimizing the size and weight of the surveying rod. Summary of the Invention

[0003] In view of the above, it is an object of the present invention to provide an improved surveying rod capable of achieving improved (e.g., accurate or at least more accurate) measurement of the length of the surveying rod while reducing the weight of the surveying rod.

[0004] According to a first aspect of the present invention, there is provided a surveying rod comprising a rod device extending along a longitudinal axis between a first end and a second end. The rod device at least comprises a first rod portion and a second rod portion which are telescopically arranged to provide length adjustment of the surveying rod.

[0005] The surveying rod further comprises a target, a top unit, and a processor. The target is arranged inside the rod device at a predetermined distance from the first end. The top unit is mounted on the second end of the rod device and extends along the longitudinal axis. The top unit comprises a positioning device, an electronic distance measurement (EDM) unit, and an optical device. The electronic distance measurement (EDM) unit is configured to determine the distance to the target, wherein the EDM unit is arranged offset relative to the longitudinal axis such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis inside the top unit. The optical device is arranged between the EDM unit and the second end of the rod device, and the optical device is adapted to redirect the optical path such that it is parallel to the longitudinal axis inside the rod device. The processor is configured to determine the length of the rod device based on the distance determined by the EDM unit.

[0006] According to a second aspect of the present invention, there is provided a method implemented in a surveying rod. The surveying rod includes a rod device extending along a longitudinal axis between a first end and a second end. The rod device at least includes a first rod portion and a second rod portion that are telescopically arranged to provide length adjustment of the surveying rod. The surveying rod further includes a target arranged inside the rod device at a predetermined distance from the first end and a top unit mounted on the second end of the rod device.

[0007] The method includes:

[0008] - Determining the distance between the EDM unit and the target using an electronic distance measurement (EDM) unit, wherein the EDM unit is arranged offset relative to the longitudinal axis (A) in the top unit such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis (A) inside the top unit,

[0009] - Redirecting the optical path such that it is parallel to the longitudinal axis inside the rod device, and

[0010] - Determining the length of the rod device based on the determined distance.

[0011] According to a third aspect of the present invention, there is provided a surveying rod that includes a rod device extending along a longitudinal axis between a first end and a second end.

[0012] The surveying rod further includes a target, a top unit, and a processor. The target is arranged inside the rod device at a predetermined distance from the first end. The top unit is mounted on the second end of the rod device and extends along the longitudinal axis. The top unit includes a positioning device, an electronic distance measurement (EDM) unit, and an optical device. The electronic distance measurement (EDM) unit is configured to determine the distance to the target, wherein the EDM unit is arranged offset relative to the longitudinal axis such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis inside the top unit. The optical device is arranged between the EDM unit and the second end of the rod device, and the optical device is adapted to redirect the optical path such that it is parallel to the longitudinal axis inside the rod device. The processor is configured to determine the length of the rod device based on the distance determined by the EDM unit.

[0013] The rod device of the surveying rod according to the third aspect may at least include a first rod portion and a second rod portion that are telescopically arranged to provide length adjustment of the surveying rod.

[0014] Alternatively, the surveying rod according to the third aspect may include a rod device of a fixed length. In other words, the length of the rod device of the surveying rod according to the third aspect may be non-adjustable.

[0015] According to a fourth aspect of the present invention, there is provided a method implemented in a surveying rod. The surveying rod includes a rod device extending along a longitudinal axis between a first end and a second end. The surveying rod further includes a target disposed inside the rod device at a predetermined distance from the first end and a top unit mounted on the second end of the rod device.

[0016] The method includes:

[0017] - Determining the distance between the EDM unit and the target using an electronic distance measurement (EDM) unit, wherein the EDM unit is disposed offset relative to the longitudinal axis (A) in the top unit such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis (A) within the top unit,

[0018] - Redirecting the optical path such that it is parallel to the longitudinal axis within the rod device, and

[0019] - Determining the length of the rod device based on the determined distance.

[0020] The rod device of the surveying rod according to the fourth aspect may at least include a first rod portion and a second rod portion that are telescopically arranged to provide length adjustment of the surveying rod.

[0021] Alternatively, the surveying rod according to the fourth aspect may include a rod device of fixed length. In other words, the length of the rod device of the surveying rod according to the fourth aspect may be non-adjustable.

[0022] According to a fifth aspect of the present invention, there is provided a top unit for a surveying rod. The top unit is configured to be mountable on a rod device extending along a longitudinal axis between a first end and a second end. The rod device includes a target disposed inside at a predetermined distance from the first end. The top unit is further configured to be mountable on the second end of the rod device and to extend along the longitudinal axis when mounted on the rod device.

[0023] The top unit includes a positioning device, an electronic distance measurement (EDM) unit, an optical device, and a processor. The EDM unit is configured to determine the distance to the target, wherein the EDM unit is disposed offset relative to the longitudinal axis such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis within the top unit. The optical device is arranged to be located between the EDM unit and the second end of the rod device when the top unit is mounted on the rod device. The optical device is adapted to redirect the optical path such that it is parallel to the longitudinal axis within the rod device. The processor is configured to determine the length of the rod device based on the distance determined by the EDM unit.

[0024] The top unit according to the fifth aspect may be detachably mounted on the rod device.

[0025] The processor can be arranged within the top unit. The processor can alternatively be outside the top unit.

[0026] The top unit according to the fifth aspect and the pole device on which the top unit is mounted can be collectively referred to as a surveying pole.

[0027] The top unit according to the fifth aspect can be mounted to a pole device that at least includes a first pole portion and a second pole portion that are telescopically arranged to provide length adjustment of the surveying pole.

[0028] The top unit according to the fifth aspect can be mounted to a pole device of fixed length. In other words, the top unit can be mounted to a pole device with non-adjustable length.

[0029] The method according to the second aspect can be suitably implemented in the surveying pole according to the first aspect. The method according to the fourth aspect can be suitably implemented in the surveying pole according to the first aspect. Thus, when implemented in such a surveying pole, any advantages described herein related to the implementation of the surveying pole equally apply to the surveying pole of the first aspect and the method of the second aspect. Additionally, as long as compatible, any advantages described herein related to the implementation of the surveying pole equally apply to the surveying pole of the third aspect and the method of the fourth aspect. Furthermore, as long as compatible, any advantages described herein related to the implementation of the surveying pole equally apply to the top unit of the fifth aspect.

[0030] The benefit provided by the present invention is that the offset position of the EDM unit relative to the longitudinal axis allows other components present within the top unit to be arranged closer to the central axis. The central axis of the top unit can coincide with the longitudinal axis.

[0031] Thus, by the present invention, compared to a top unit in which the EDM unit is centered relative to the longitudinal axis, the diameter of the top unit can be reduced. The reduced size is advantageous in terms of storage and transportation of the surveying pole. Due to the reduced diameter, the weight of the top unit can also be reduced, which is beneficial to the operator of the surveying pole. Another advantage of the reduced weight is that the top unit is more resistant to falling. In the case of a fall, a higher weight would result in a higher energy impact. Thus, the present invention reduces the possible damage to the top unit and the components within the top unit in the case of a fall.

[0032] With the present invention, the EDM unit can be arranged within the top unit without increasing the longitudinal dimension or height of the top unit. It should be noted that although arranging the EDM unit to be aligned with the central axis and arranging all or part of the other components within the top unit above the EDM unit would also result in a decrease in the diameter of the top unit, this in turn would cause a significant increase in the longitudinal dimension of the top unit. This may not be desirable as there may be practical limitations to the longitudinal dimension of the top unit. For example, it may be desirable to allow the top unit to be transported within a box of a specific size.

[0033] Another advantage of the present invention is that by arranging the EDM unit within the top unit, a conventional hollow surveying rod device can be used without at least significant modifications.

[0034] In at least one example embodiment, the optical device can be adapted to redirect the optical path such that it coincides with the longitudinal axis within the rod device.

[0035] The positioning device can include a reflective element, a light-emitting element, and / or a GNSS (Global Navigation Satellite System) antenna, or any combination thereof. The positioning device can be configured to cooperate passively with a geodetic instrument (such as a theodolite or total station). It can be configured to cooperate actively with a geodetic instrument, for example for tracking purposes.

[0036] The top unit can include additional elements, such as an inclination sensor, for example for determining the inclination angle between the longitudinal axis and the vertical direction.

[0037] The top unit can include a communication device, for example for transmitting the determined length of the rod device to an external unit or instrument. Alternatively, the distance between the contact point of the surveying rod with the terrain and the positioning device can be calculated based on the determined length of the surveying rod and the fixed distances of the surveying rod (such as the distance between the contact point with the terrain and the target, and the distance between the EDM unit and the positioning device). For example, the determined length or the calculated distance can be transmitted to a geodetic instrument cooperating with the surveying rod. Alternatively, the determined length or the calculated distance can be transmitted to a separate, optional mobile control unit.

[0038] The optical device can include at least one optical element selected from the group including prisms, mirrors, optical waveguides, and combinations thereof.

[0039] The optical waveguide can include, for example, optical fibers. In principle, any optical element or combination of optical elements suitable for guiding light and thus providing the required optical path within the rod device can be used.

[0040] This provides freedom in the arrangement of the EDM unit within the top unit.

[0041] The prism can be a triangular prism. For example, the prism can be a right prism. Alternatively, the prism can be a rhombic prism or a pentaprism.

[0042] In at least one exemplary embodiment, the optical device can include two prisms. Alternatively, the optical device can include two mirrors, or one prism and one mirror.

[0043] For example, the optical device can include two triangular prisms, or one triangular prism and one mirror.

[0044] The advantage of a prism is that it is more durable than a mirror. In particular, in the case where the top unit is impacted (e.g., due to a fall or an external object), the prism may be less likely to be damaged. The prism also provides better light transmission than a mirror. The production of a mirror may be cheaper than that of a prism. The mirror may also be much lighter than the prism.

[0045] Light can be emitted along the optical path by the laser of the EDM unit.

[0046] The EDM unit can be shiftable to be able to adjust the optical path in the rod device.

[0047] The optical device can include at least one shiftable element to be able to adjust the optical path in the rod device.

[0048] Therefore, the optical path in the rod device can be adjusted by the shift of the EDM unit and / or the shift of at least one element of the optical device.

[0049] This enables the calibration of the EDM unit. This is advantageous because it allows the EDM unit to be calibrated at a later stage in the manufacture or assembly of the top unit. It can reduce the precision with which the EDM unit has to be installed within the top unit, thereby making the manufacture or assembly of the top unit less complex and / or less costly. Then, the required precision of the instrument can be obtained in the calibration step. For this purpose, the top unit can be arranged on a calibration table, and the position of the EDM unit and / or the position of the shiftable element of the optical device can be adjusted to obtain the required optical path of the light emitted by the EDM unit.

[0050] The advantage of achieving the adjustment by the shift of the elements of the optical device is that it is smaller in size. In other words, the shiftable element of the optical device is generally smaller than the EDM unit. Therefore, replacing such an element requires less space than replacing the EDM unit. In addition, when the adjustment is made by the shift of the elements of the optical device, the adjustment system necessarily bears less weight than when carrying the EDM unit. This can make the system more durable.

[0051] The optical device can include at least one fixed prism having a surface that faces the inside of the rod device when the top unit is mounted on the rod device.

[0052] Thus, the light emitted by the EDM unit can directly leave (or enter, after being reflected by the target) the top unit through at least one prism. In other words, no other optical elements (such as optical windows) are required to allow the light to leave (or enter) the top unit.

[0053] In such an optical device, at least one fixed prism can be sealingly fixed to the top unit to provide a seal between the interior of the top unit and the interior of the rod device.

[0054] Thus, a protected environment can be created for the components present in the top unit. That is, the light emitted by the EDM unit / reflected by the target is allowed to leave / enter the top unit while preventing the interior of the top unit from being contaminated by, for example, dust or other particles.

[0055] The top unit can be detachably mounted or detachably mountable on the rod device.

[0056] This can allow the top unit to be used with different rod devices. In particular, depending on the needs of the current application, such a top unit can be easily transferred between different rod devices. For example, such a top unit can be mounted on rod devices having different heights or lengths, stiffness, or other characteristics. If the rod device is damaged, the detachably mounted top unit can be easily switched to a functioning rod device.

[0057] Thus, the top unit can be used with different fixed-length rod devices. Although in some cases the length of such a fixed-length rod device may be known, the present invention provides the advantage that the length of the rod device can be automatically obtained. In other words, the nominal length of the rod device can be automatically verified.

[0058] The top unit can include a battery for powering the positioning device and the EDM unit. The battery can also power other components present in the top unit. Thus, the top unit or the components therein may not require power supply from an external power source. In particular, no external power source is required on or within the rod device. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Aspects of the present invention, including its specific features and further advantages, will now be described with reference to the accompanying drawings, in which:

[0060] Figure 1 A typical scenario of the surveying rod according to the present invention in use is shown,

[0061] Figure 2a and Figure 2b The rod device of one embodiment of the surveying rod is schematically shown,

[0062] Figure 3 is shown in more detail schematicallyFigure 1 the top unit of the surveying pole,

[0063] Figures 4a - 4c schematically shows an alternative configuration of the optical device, and

[0064] Figure 5 is a flowchart showing the method according to the present invention. Detailed Description

[0065] Figure 1 shows a typical scenario of the surveying pole 1 according to the present invention in use. The surveying pole 1 is used to determine the three-dimensional position of a point of interest 10.

[0066] The surveying pole 1 includes a pole device 100 extending along a longitudinal axis A between a first end 101 and a second end 102. As shown, the pole device 100 includes a first pole portion 105 and a second pole portion 106 that are telescopically arranged to provide length adjustment of the surveying pole 1. A target 111 ( Figure 1 not visible in the figure) is internally arranged in the pole device 100. The pole arrangement will be described in more detail in conjunction with Figure 2a and Figure 2b more details.

[0067] Although a telescopic pole device is shown in the figure, the pole device can also be a pole device with a fixed length. In other words, the length of the pole device can be non-adjustable. Thus, the top unit can be used with interchangeable pole devices having different fixed lengths or different adjustable lengths.

[0068] The top unit 104 is mounted on the second end 102 of the pole device 100 and extends along the longitudinal axis A. The top unit 104 includes a positioning device 107, which may include a reflecting element 108, a light-emitting element 109, and / or a GNSS (Global Navigation Satellite System) antenna 110.

[0069] The top unit 104 also includes an electronic distance measurement (EDM) unit 112 ( Figure 1 not visible in the figure), which is configured to determine the distance to the target 111. As Figure 3 more easily seen, the EDM unit 112 is offset relative to the longitudinal axis A such that a portion 113 of the optical path 114 between the EDM unit 112 and the target does not coincide with the longitudinal axis A in the top unit 104.

[0070] The top unit 104 also includes an optical device 200 ( Figure 1 not visible in the figure), which is arranged between the EDM unit 112 and the second end 102 of the pole device 100. The optical device 200 is adapted to redirect the optical path 114 such that it is parallel to the longitudinal axis A within the pole device. Figure 3An example of the optical device 200 is shown, Figures 4a - 4c and an alternative configuration of the optical device 200 is shown.

[0071] The surveying rod 1 further includes a processor 115 configured to determine the length of the rod device 100 based on the distance determined by the EDM unit 112. In this example, the processor 115 is shown as being disposed within the top unit 104.

[0072] The pointing tip 103 is mounted at the first end 101 of the rod device 100. When using the surveying rod 1, when making a measurement at an interesting point 10 on the terrain or structure, the pointing tip 103 is placed on the interesting point 10. Generally, during the measurement process, the surveying rod 1 is held in a vertical position. Thus, in use, the pointing tip 103 is the lowest part of the surveying rod 1, while the top unit 104 is located at the highest part of the surveying rod 1. Hereinafter, when referring to the surveying rod 1, a part thereof, and / or an element contained therein, as described above, expressions such as above, higher than, below, lower than, etc. should be interpreted as referring to when the surveying rod 1 is in a typical use position. More precisely, such expressions should be interpreted as, when using the surveying rod 1, an element above or higher than another element is closer to the sky along the longitudinal axis A than that other element; conversely, an element below or lower than another element is closer to the interesting point 10 along the longitudinal axis A than that other element.

[0073] The first step in determining the position of the interesting point 10 is to determine the position of the positioning device 107.

[0074] In Figure 1 the example, the position of the positioning device 107 can be determined in cooperation with a geodetic instrument (here shown as a total station 117 mounted on a tripod 118 and located above the reference point 11). The total station 117 includes a sighting instrument 119 rotatable about a first axis (not shown) and a central unit 120 rotatable about a second axis (not shown). Generally, the total station is set such that in use, the first axis and the second axis are vertical and horizontal, respectively. The first axis and the second axis intersect within the central unit 120 such that the aiming axis 121 of the total station 117 can rotate about the intersection of the axes. The central unit 120 may include one or more measuring devices, such as an EDM unit. In addition, the central unit 120 may include one or more sensors (such as a camera and / or a light detector), and a control unit for controlling the measuring devices and the sensors. The total station 117 is equipped with sensors, such as an angle sensor and / or an accelerometer or an inertial measurement unit, for determining the orientation of the aiming axis 121.

[0075] The reference point 11 may have a known position, e.g., a position in a common reference system. To determine the position of the point of interest 10 relative to the reference point 11, the EDM unit of the central unit 120 may measure, for example, the distance between the positioning device 107 of the surveying rod 1 and the total station 117 based on the light emitted by the EDM unit towards the positioning device 107 and reflected back towards the total station 117 by the reflecting element 108 of the positioning device 107. Then, the position of the positioning device 107 can be derived based on the measured distance and the orientation of the aiming axis 121.

[0076] Alternatively or additionally, the GNSS antenna 110 or receiver may receive positioning data from GNSS (illustrated by a plurality of satellites 116).

[0077] Knowing the position of the positioning device 107, the position of the point of interest can be derived based on the distance between the positioning device and the point of interest 10, i.e., the distance between the positioning device 107 and the tip 103 (of the pointing tip). For this purpose, the length of the rod device 100 of the surveying rod 1 needs to be accurately measured. This measurement is provided by the surveying rod 1 according to the invention, which will be explained in more detail below.

[0078] It should be noted that in Figure 1 the illustrated scenario, the aiming axis 121 of the total station 117 is unobstructed between the total station 117 and the positioning device 107 of the surveying rod 1.

[0079] There may be situations where, in the case of an obstacle between the total station 117 and the positioning device 107, it is necessary to measure the point of interest. Adjusting the length of the surveying rod 1 to move the positioning device 107 upwards can then provide a direct line of sight between the total station 117 and the positioning device 107. Conversely, adjusting the length of the surveying rod 1 to a shorter length may be desirable, for example, if an object above the point of interest (such as a tree branch or a part of a structure such as a roof) obstructs the positioning of the surveying rod at the point of interest. Generally, a surveying rod 1 with an adjustable length provides higher flexibility in positioning and improved maneuverability for the operator of the surveying rod 1.

[0080] As mentioned above, the top unit 104 may also be mounted on a rod device of a fixed length. Thus, the operator can select a rod device of an appropriate length for a specific application. For example, a longer rod device can be selected to provide a direct line of sight between the total station 117 and the positioning device 107 above an obstacle, or a shorter rod device can be selected to allow operation under overhanging objects or structures.

[0081] Figure 2a and Figure 2b The rod device 100 of the surveying rod 1 is shown schematically in more detail, where Figure 2ashows the rod device in the retracted position (the rod device 100 is shorter), Figure 2b and shows the rod device in the extended position (the rod device 200 is longer). In Figure 2a and Figure 2b for the sake of clarity of the figure, the proportions of the different elements of the surveying rod 1, especially the proportion of the rod device 100, are exaggerated. Therefore, Figure 2a and Figure 2b the surveying rod 1 in

[0082] is not shown to scale. Figure 2a and Figure 2b Thus, Figure 2a and Figure 2b show the surveying rod 1, the top unit 104 of which is mounted on the rod device 100. In this example, the rod device 100 includes two rod portions 105, 106 that are telescopically arranged to provide length adjustment of the surveying rod: a first rod portion 105 that includes the first end of the rod device 100; and a second rod portion 106 that includes the second end 102 of the rod device 200. As

[0083] shown by the different positions of the second rod portion 106 in

[0084] the second rod portion 106 can move telescopically within the first rod portion 105. In other words, the cross-section of the second rod portion 106 is smaller than the cross-section of the first rod portion 105, such that the second rod portion 106 can be radially assembled inside the first rod portion 105. Another different arrangement is also possible, for example, the second rod portion 106 has a larger cross-section than the first rod portion 105, and the first rod portion 105 can move telescopically within the second rod portion 106. It is also conceivable to have a rod device 100 with more than two rod portions.

[0085] The ring 122 is mounted at the lower end of the second rod portion 106.

[0086] As Figure 2a and Figure 2bAs shown, the outer tube 123 of the second rod portion 106 may optionally have a plurality of holes or openings 125 for receiving fixing means, such as locking pins (not shown) for locking the position of the rod portion, thereby fixing the positioning of the rod portions 105, 106 relative to each other. The first rod portion 105 may include corresponding holes or openings (not shown) for the same purpose. When using a locking pin, care should be taken not to block the optical path 114, as blocking the optical path 114 will prevent the EDM unit from performing the required measurements. In particular, it may not be appropriate to use a locking pin that passes through the entire diameter of the first rod portion 105 and / or the second rod portion 106. The relative positions of the fixed rod portions 105, 106 may alternatively be achieved by a friction mechanism. Those skilled in the art will be familiar with different alternatives for fixing the telescopic rod portions 105, 106 in the desired positions.

[0087] The pointing tip 103 for contacting the point of interest to be measured is mounted at the first end 101 of the first rod portion 105.

[0088] In this example, the target 111 is arranged in the first rod portion 105, near the first end 101 and above the pointing tip 103. Different placements of the target 111 are possible, as long as the placement of the target 111 does not hinder the length adjustment of the surveying rod (i.e., it does not prevent the telescopic displacement of the second rod portion 106), and as long as the distance between the target 111 and the first end 101 remains constant when adjusting the length of the surveying rod. The target 111 is longitudinally spaced from the first end 101 by a distance 126, and thus is at a certain distance from the tip of the pointing tip 103. The distance 126 may be, for example, 5 cm to 45 cm, or 10 cm to 40 cm, or 15 cm to 35 cm. In particular, the distance 126 may be 30 cm. This can ensure that in most cases, the target is above the level during the measurement.

[0089] Figure 2a and Figure 2b Also shown in is the optical path 114 between the EDM unit 112 and the target 111 within the rod device 100. As described above, the optical path 114 is parallel to the longitudinal axis A within the rod device 100. In particular, as shown, the optical path 114 may coincide with the longitudinal axis A within the rod device 100.

[0090] The top unit 104 may be mounted on the rod device 100 by any suitable fastening means, such as screws, bolts, threads, etc. (not shown in the figure). In particular, the top unit 104 may be detachably mounted on the rod device.

[0091] In an embodiment where the rod device has a fixed length (not shown in the figure), in addition to the length adjustment ability, the rod device may have characteristics similar to those of the rod device described above.

[0092] Figure 3 The schematic diagram of Figure 3 shows the top unit 104 in more detail.

[0093] Figure 3 The top unit 104 shown includes all the components of the top unit described in Figure 1 , namely the positioning device 107, the EDM unit 112, the processor 115, and the optical device 200. In addition, the top unit 104 further includes a power supply or battery 129 for powering the components arranged within the top unit 104. The top unit 104 also includes a communication device 127 which can be configured to transmit the determined length of the rod device 100, or the calculated distance between the pointing tip 103 and the positioning device 107, to an external unit or instrument. For example, in Figure 1 the scenario shown, the communication device 127 can be configured to transmit the determined or calculated length to the total station 117.

[0094] The top unit 104 is mounted on the rod device 100. In Figure 3 , only the second rod portion 106 and the second end 102 of the rod device 100 are shown.

[0095] As Figure 3 clearly shown, the EDM unit 112 is arranged offset with respect to the longitudinal axis A. Thus, the EDM unit 112 emits light along an optical path which has a portion 113 within the top unit 104 that does not coincide with the longitudinal axis A. The optical device 200 is arranged between the EDM unit 122 and the second end 102 of the rod device 100 and is configured to redirect the optical path 114 such that it is parallel to the longitudinal axis A within the rod device 100. In particular, the optical path 114 can coincide with the longitudinal axis A as shown here.

[0096] In this example, the optical device 200 includes a first right-angled triangular prism 201 and a second right-angled triangular prism 202. Thus, the light emitted by the EDM unit 112 first enters the first prism 201, whereby the optical path 114 is redirected to the second prism 202, and the second prism 202 in turn redirects the optical path 114 such that it is parallel to the longitudinal axis A within the rod device 100.

[0097] The second prism 202 is fixed within the top unit 104. The second prism 202 is also provided with a surface 204 which faces the interior of the rod device 100 when the top unit 104 is mounted on the rod device 100. In other words, the second prism 202 provides for the departure and entry of the optical path 114 from the top unit 104. In addition, the second prism 202 is fixedly sealed to the top unit 104 to provide a seal between the interior of the top unit 104 and the interior of the rod device 100. In particular, the seal is provided by the ring 203.

[0098] Adjustment of the optical path 114 is provided by shifting the first prism 201. In particular, the first prism 201 can be mounted on a support structure 204, the orientation of which is adjustable. For example, the orientation of the support structure 204 can be adjusted by adjusting screws 205. In an alternative not shown in the figures, adjustment of the optical path 114 can instead be provided by shifting the EDM unit.

[0099] Referring Figure 2a , Figure 2b and Figure 3 , the distance between the EDM unit 112 and the target 111 is determined by the EDM unit 12. To this end, the EDM unit 112 emits a light beam along the optical path 114, typically by means of a laser in the EDM unit 112. As described above, the first part 113 of the optical path 114 (within the top unit) does not coincide with the longitudinal axis A. The optical device 200 redirects the optical path 114 such that it is parallel to the longitudinal axis A within the rod device 100. When the light beam reaches the target 111, it is reflected back along the same optical path 114 towards the EDM unit 112. The EDM unit 112 then calculates the distance between the EDM unit 112 and the target 111 based on the travel time of the light beam from the EDM unit 112 to the target 111 and back to the EDM unit 112. Knowing some fixed lengths of the surveying rod 1, such as the distance between the EDM unit 112 and the positioning device 107, and the distance between the target 111 and the pointing tip 103, the distance between the pointing tip 103 and the positioning device 107 can be derived.

[0100] The optical device 200 can include two mirrors 206, 207 instead of two prisms 201, 202, as Figure 4a shown. In this case, the orientation of one or both of the mirrors 206, 207 can be adjustable to provide adjustment of the optical path 114. The mechanism for moving the mirrors 206 and / or 207 can be similar to the mechanism for moving the first prism 201 described above. However, the support structure or adjustment mechanism for the mirrors 206, 207 is not shown in the figures. In Figure 4a the configuration, the seal between the interior of the top unit 104 and the interior of the rod device 100 is provided by the optical window and the ring 203.

[0101] Another alternative arrangement of the optical device 200 is as Figure 4b shown. This alternative combines a fixed right-angled prism 201 as Figure 3 shown and a mirror 206 as Figure 4a shown. Adjustment of the optical path 114 is advantageously provided by shifting the mirror 206.

[0102] Figure 4cShows yet another alternative arrangement. In this example, the optical device 200 includes a fixed rhombic prism 208. Adjustment of the optical path 114 is provided by shifting the EDM unit 112. For example, the EDM unit 112 can be mounted on a support structure that has means for adjustment, similar to that described for the first prism as shown in Figure 3 However, Figure 4c the support structure or the adjustment means are not shown.

[0103] As shown and described above, the EDM unit is arranged offset with respect to the longitudinal axis A. Note that the EDM unit 112 can be arranged such that a portion 113 of the optical path 114 within the top unit 104 is not parallel to the longitudinal axis A, for example in the configurations of Figure 3 as well as Figure 4a and Figure 4b . The EDM unit 112 can also be arranged such that a portion 113 of the optical path 114 within the top unit 104 is generally parallel to the longitudinal axis A. In this regard, the selected arrangement of the EDM unit 122 and the ultimate orientation of the portion 113 of the optical path 114 within the top unit 104 may depend on the selected configuration of the optical device 200 (and vice versa).

[0104] Although not shown in the figures, other alternatives for the optical device 200 are possible. For example, a pentaprism can be used. More generally, the optical device 200 can include any type of light guide. For example, an optical fiber can also be used to guide the optical path 114 within the top unit 104.

[0105] It is contemplated that regardless of the configuration selected for the optical device, adjusting the optical path 114 is performed as a calibration operation, as a step during the manufacturing / assembly process of the top unit 104 or during the servicing of the surveying rod. Thus, adjusting the optical path 114, for example by manipulating the adjustment screws as described above, is done by trained personnel in a controlled environment.

[0106] Referring to Figure 5 , a method 500 according to one aspect of the present invention will now be described. As described above, the method is implemented in the surveying rod 1. The method can also be implemented by the top unit 104 as described above.

[0107] In step 501, the EDM unit 112 emits a beam along a first portion 113 of the optical path 114 such that the first portion 113 does not coincide with the longitudinal axis A.

[0108] In step 502, the optical device 200 redirects the optical path 114 so that it is parallel to the longitudinal axis A within the rod device.

[0109] The beam reaches the target 111 and then reflects back along the optical path 114 towards the EDM unit 112.

[0110] In step 503, the EDM unit 112 determines the distance between the EDM unit 112 and the target 111, for example, based on the travel time of the light beam emitted by the EDM unit 12.

[0111] In step 504, the processor 115 determines the length of the rod device 100 based on the distance between the EDM unit 112 and the target 111 determined by the EDM unit 112.

[0112] In an optional step 505, the determined length of the rod device 100 or the distance between the pointing tip 103 and the positioning device 107 derived therefrom is transmitted to an external unit or instrument, such as an optional mobile control unit or a total station 117 cooperating with the surveying rod 1.

[0113] The method can also be generalized to include the step of using the EDM unit 112 to determine the distance between the EDM unit 112 and the target 111, where the EDM unit 112 is arranged offset with respect to the longitudinal axis A in the top unit 104 such that at least a part 113 of the optical path 114 between the EDM unit 112 and the target 111 does not coincide with the longitudinal axis A within the top unit 104. To this end, the method further includes the following steps: redirecting the optical path 114 such that it is parallel to the longitudinal axis A within the rod device 100. The method further includes the following steps: determining the length of the rod device, in particular by the processor 115, based on the distance determined by the EDM unit 112.

[0114] Although the features and elements have been described above in specific combinations, each feature or element can be used alone without the other features and elements, or in various combinations with or without the other features and elements.

[0115] In addition, by studying the drawings, the description of the invention, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" does not exclude a plurality.

[0116] List of Embodiment Details

[0117] Item 1. A surveying rod, comprising:

[0118] A rod device extending along a longitudinal axis (A) between a first end and a second end, the rod device including at least a first rod portion and a second rod portion arranged telescopically to provide length adjustment of the surveying rod;

[0119] A target arranged inside the rod device at a predetermined distance from the first end;

[0120] A top unit, which is mounted on the second end of the rod device and extends along the longitudinal axis (A), the top unit comprising:

[0121] Positioning equipment,

[0122] An electronic distance measurement (EDM) unit, the EDM unit being configured to determine the distance to the target, wherein the EDM unit is offset relative to the longitudinal axis (A) such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis (A) within the top unit, and

[0123] An optical device, which is arranged between the EDM unit and the second end of the rod device, the optical device being adapted to redirect the optical path such that the optical path is parallel to the longitudinal axis within the rod device; and

[0124] A processor, the processor being configured to determine the length of the rod device based on the distance determined by the EDM unit.

[0125] Item 2. The surveying rod according to item 1, wherein the optical device includes at least one optical element selected from the group consisting of prisms, mirrors, optical waveguides, and combinations thereof.

[0126] Item 3. The surveying rod according to item 2, wherein the prism is a triangular prism, a rhombic prism, or a pentagonal prism.

[0127] Item 4. The surveying rod according to item 2, wherein the optical device includes two prisms, or two mirrors, or one prism and one mirror.

[0128] Item 5. The surveying rod according to any one of the preceding items, wherein light is emitted along the optical path by the laser of the EDM unit.

[0129] Item 6. The surveying rod according to any one of the preceding items, wherein the EDM unit is displaceable to be able to adjust the optical path in the rod device.

[0130] Item 7. The surveying rod according to any one of the preceding items, wherein the optical device includes at least one displaceable element to be able to adjust the optical path in the rod device.

[0131] Item 8. The surveying rod according to any one of the preceding items, wherein the optical device includes at least one fixed prism having a surface that faces the inside of the rod device when the top unit is mounted on the rod device.

[0132] Item 9. The surveying rod according to item 8, wherein the at least one fixed prism is fixedly secured to the top unit in a sealed manner to provide a seal between the interior of the top unit and the interior of the rod device.

[0133] Item 10. The surveying rod according to any one of the preceding items, wherein the top unit is detachably mounted on the rod device.

[0134] Item 11. The surveying rod according to any one of the preceding items, wherein the top unit includes a battery for powering the positioning device and the EDM unit.

[0135] Item 12. A method implemented in a surveying rod, the surveying rod comprising: a rod device extending along a longitudinal axis (A) between a first end and a second end, the rod device including at least a first rod portion and a second rod portion arranged telescopically to provide length adjustment of the surveying rod; a target arranged inside the rod device at a predetermined distance from the first end; and a top unit mounted on the second end of the rod device.

[0136] The method includes:

[0137] Determining a distance between the EDM unit and the target using an electronic distance measurement (EDM) unit, wherein the EDM unit is arranged offset with respect to the longitudinal axis (A) in the top unit such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis (A) inside the top unit,

[0138] Redirecting the optical path such that the optical path is parallel to the longitudinal axis (A) inside the rod device, and

[0139] Determining the length of the rod device based on the determined distance.

Claims

1. A surveying rod, comprising: a rod arrangement extending along a longitudinal axis (A) between a first end and a second end; a target disposed inside the rod device at a predetermined distance from the first end; a top unit mounted on the second end of the rod means and extending along the longitudinal axis (A), the top unit comprising: Positioning equipment, an electronic distance measurement (EDM) unit configured to determine the distance to the target, wherein the EDM unit is arranged offset relative to the longitudinal axis (A) such that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis (A) within the top unit, and an optical device arranged between the EDM unit and the second end of the rod device, the optical device being adapted to redirect the optical path such that the optical path is parallel to the longitudinal axis within the rod device; and A processor is configured to determine a length of the rod arrangement based on the distance determined by the EDM unit.

2. The surveying rod according to claim 1, wherein: The optical device includes at least one optical element selected from the group consisting of a prism, a mirror, a light guide, and combinations thereof.

3. The surveying rod according to claim 2, wherein: The prism is a triangular prism, a rhombus prism, or a pentaprism.

4. The surveying rod according to claim 2, wherein: The optical device includes two prisms, or two reflectors, or a prism and a reflector.

5. The surveying rod according to any one of claims 1 to 4, wherein: Light is emitted along the optical path by a laser of the EDM unit.

6. The surveying rod according to any one of claims 1 to 5, wherein: The EDM unit is displaceable to enable adjustment of the optical path in the rod arrangement.

7. The surveying rod according to any one of claims 1 to 6, wherein: The optical arrangement comprises at least one displaceable element to be able to adjust the light path in the rod arrangement.

8. The surveying rod according to any one of claims 1 to 7, wherein: The optical device includes at least one fixed prism having a surface facing the interior of the pole device when the top unit is mounted on the pole device.

9. The surveying pole according to claim 8, wherein: The at least one fixed prism is sealingly secured to the top unit to provide a seal between an interior of the top unit and an interior of the pole arrangement.

10. The surveying pole according to any one of claims 1 to 9, wherein: The top unit is detachably mounted on the pole arrangement.

11. The surveying pole according to any one of claims 1 to 10, wherein: The top unit includes a battery for powering the positioning device and the EDM unit.

12. The surveying pole according to any one of claims 1 to 11, wherein: The pole arrangement comprises at least a first pole portion and a second pole portion telescopically arranged to provide length adjustment of the surveying pole.

13. A method implemented in a surveying pole, the surveying pole comprising: a rod arrangement extending along a longitudinal axis (A) between a first end and a second end; a target disposed within the interior of the rod assembly at a predetermined distance from the first end; and a top unit mounted on said second end of said rod means, The method comprises: determining the distance between the EDM unit and the target using an electronic distance measuring EDM unit, wherein the EDM unit is arranged offset relative to the longitudinal axis (A) in the top unit so that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis (A) in the top unit, redirecting the optical path such that it is parallel to the longitudinal axis (A) within the rod arrangement, and The length of the rod arrangement is determined based on the determined distance.

14. The method according to claim 13, wherein: The pole arrangement comprises at least a first pole portion and a second pole portion telescopically arranged to provide length adjustment of the surveying pole.

15. A top unit for a surveying pole, the top unit being configured to be mountable on a pole arrangement extending along a longitudinal axis (A) between a first end and a second end, in, The rod device comprises a target arranged inside the rod device at a predetermined distance from the first end, wherein the top unit is further configured to be mountable on the second end of the pole device and to extend along the longitudinal axis (A) when mounted on the pole device, Wherein, the top unit comprises: Positioning equipment, an electronic distance measurement (EDM) unit configured to determine the distance to the target, wherein the EDM unit is arranged offset relative to the longitudinal axis (A) so that at least a portion of the optical path between the EDM unit and the target does not coincide with the longitudinal axis (A) in the top unit, an optical device arranged between the EDM unit and the second end of the rod device when the top unit is mounted on the rod device, the optical device being adapted to redirect the light path such that the light path is parallel to the longitudinal axis (A) within the rod device, and A processor is configured to determine a length of the rod arrangement based on the distance determined by the EDM unit.

Images