Devices and methods for determining survey data

Abstract

Apparatus and corresponding methods for determining survey data relating to a feature of a land area, the apparatus comprising: a measuring device including: a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device; a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use; and a measuring device computer processor configured to: obtain first motion data from the plurality of inertial sensors while the measuring device is stationary at a first survey location relating to the feature; obtain second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location; control, based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location, the apparatus further comprising a processing device comprising a processing device computer processor configured to: determine an X, Y and Z position of the first survey location based on the first motion data; determine an X, Y and Z position of the measuring device based on the second motion data; determine a distance from the measuring device to the ground level based on the obtained distance data; and generate survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

Description

[0001] DEVICES AND METHODS FOR DETERMINING SURVEY DATA

[0002] Technical field

[0003] The invention relates to methods and apparatus for determining survey data. In particular, the invention may relate to, but need not be limited to, methods and apparatus for determining coordinates (such as X, Y and Z coordinates) of a feature of a land area.

[0004] Background

[0005] When preparing for and undertaking work onsite, landscapers and other construction professionals may need to understand the X, Y and Z position of a feature of a land area in which they are working. The X, Y and Z position in this case may refer to a local coordinate system. This can allow, for example, accurate estimates of spoil volume for earthworks and / or accurate estimates of materials, time and resource needed as part of the work to be undertaken.

[0006] Traditional techniques include the use of tape measures to determine a 2-dimensional (e.g. X and Y coordinate) estimation of a land area, although this takes no account of changing gradient over the area. A level may be used in conjunction with tape measures in order to measure relative elevation of the ground at a number of points within the area and thereby estimate the topography. However, these methods are time consuming, require two or more construction professionals to carry out and can suffer from significant inaccuracies.

[0007] Greater Accuracy can be obtained using a total station to measure relative elevation of the ground at a number of points within the area. However, a total station is an expensive piece of surveying equipment requiring significant skill and experience to operate and is not suitable for the majority of smaller construction or landscaping projects.

[0008] In addition, it is possible to use an inertial based measurement tool that can be placed on the ground at a plurality of points related to the feature to be surveyed. The motion sensors forming part of such devices record data allowing the relative elevation of each of the plurality of points to be measured. Such systems work well but are limited in accuracy based on the number of points within the area that the device is placed at. It can also be time consuming to have to manually place the device at the plurality of points in the area. There is a need for an accurate, efficient and cost effective method for determining a topography of a land area that can be implemented by any construction worker without significant training or experience.

[0009] Summary

[0010] Methods and apparatus disclosed herein are directed to solving one or more problems in the prior art, including those disclosed herein.

[0011] According to an aspect of the invention, there is provided an apparatus for determining topographic data relating to a surface, the apparatus comprising: a measuring device including a plurality of sensors configured to obtain data representing position of the measuring device, the measuring device further comprising a distance measurer configured to obtain distance data representing a distance from the measuring device to the surface; and a processing device comprising a computer processor configured to: determine a position of the measuring device based on the obtained data; determine a distance from the measuring device to the surface based on the obtained distance data; and generate a topographic data for the surface based on the determined position and determined distance.

[0012] Optionally, the data further represents orientation of the measuring device, and optionally wherein the data is obtained based on rotational and linear movement of the measuring device in a body frame comprising orthogonal x, y and z axes.

[0013] Optionally, the surface includes at least part of a ground surface of a land area.

[0014] Optionally, the determined distance includes a vertical distance from the measuring device to the surface, the computer processor being configured to determine the vertical distance based on the obtained distance data and the obtained data.

[0015] Optionally, the computer processor is configured to control the distance measurer to obtain the distance data.

[0016] Optionally, the computer processor is configured to control the distance measurer to obtain the distance data based on an elapsed time. Optionally, the computer processor is configured to control the distance measurer to obtain the distance data based on the position of the measuring device and, optionally, at specific two-dimensional positions.

[0017] Optionally, the apparatus is a handheld tool for use by a construction worker.

[0018] Optionally, the sensors comprise inertial sensors and / or wherein the sensors form an inertial measurement unit.

[0019] Optionally, the sensors may be motion sensors and may consist of inertial sensors. That is, data representing position and / or orientation of the measuring device may be obtained using only inertial sensors. The inertial sensors may be MEMs sensors. This allows the device to have a form factor small enough to be handheld for use by a construction professional.

[0020] Optionally, the distance measurer comprises a signal transmitter and a signal receiver, wherein the signal transmitter is arranged to transmit a signal that is reflectable from the surface, and wherein the signal receiver is configured to receive the reflected signal, the distance data comprising a time of flight of the emitted and reflected signals.

[0021] Optionally, the distance measurer is configured to measure linear distance up to 50 metres, up to 25 metres, up to 10 metres or up to 5 metres.

[0022] Optionally, the distance measurer includes a laser distance measurer.

[0023] Optionally, the distance measurer provides a visible guide allowing a user of the apparatus to see a point on the surface that the distance data is being measured to.

[0024] Optionally, the visible guide includes a marker projected from the measuring device onto the surface.

[0025] Optionally, the processing device is separate to the measuring device, and wherein the measuring device comprises a transmitter configured to transmit the obtained data and the obtained distance data, and the processing device comprises a receiver configured to receive the transmitted data.

[0026] According to an aspect of the invention, there is provided a method of determining topographic data relating to a surface, the method comprising: obtaining data representing position of a measuring device using sensors; obtaining distance data representing a distance from the measuring device to a surface using a distance measurer; determining a position of the measuring device based on the obtained data; determining a distance from the measuring device to the surface based on the obtained distance data; and generating a topographic data for the surface based on the determined position and determined distance.

[0027] According to an aspect of the invention, there is provided a processing device for determining topographic data relating to a surface, the processing device comprising: a receiver configured to receive: data, measured by a plurality of sensors and representing position a measuring device; and distance data, obtained by a distance measurer and representing a distance from the measuring device to the surface, the processing device further comprising a computer processor configured to: determine a position of the measuring device based on the received data; determine a distance from the measuring device to the surface based on the received distance data; and generate a topographic data for the surface based on the determined position and determined distance.

[0028] According to an aspect of the invention, there is provided a method of determining topographic data relating to a surface, the method comprising: receiving data, measured by a plurality of sensors and representing position a measuring device; and receiving distance data, obtained by a distance measurer and representing a distance from the measuring device to the surface, determining a position of the measuring device based on the received data; determining a distance from the measuring device to the surface based on the received distance data; and generating a topographic data for the surface based on the determined position and determined distance.

[0029] According to an aspect of the invention, there is provided a measuring device for determining topographic data relating to a surface, the measuring device comprising: a plurality of sensors configured to obtain data representing position of the measuring device; a distance measurer configured to obtain distance data representing a distance from the measuring device to the surface; and a transmitter configured to transmit the obtained data and the obtained distance data to a processing device.

[0030] According to an aspect of the invention, there is provided a method of determining topographic data relating to a surface, the method comprising: obtaining data representing position of a measuring device using sensors; obtaining distance data representing a distance from the measuring device to a surface using a distance measurer; and transmitting the obtained data and the obtained distance data to a processing device. According to an aspect of the invention, there is provided an apparatus for determining survey data relating to a feature of a land area, the apparatus comprising: a measuring device including: a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device; a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use; and a measuring device computer processor configured to: obtain first motion data from the plurality of inertial sensors while the measuring device is stationary at a first survey location relating to the feature; obtain second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location; control, based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location, the apparatus further comprising a processing device comprising a processing device computer processor configured to: determine an X, Y and Z position of the first survey location based on the first motion data; determine an X, Y and Z position of the measuring device based on the second motion data; determine a distance from the measuring device to the ground level based on the obtained distance data; and generate survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

[0031] Optionally, the motion data further represents orientation of the measuring device, and optionally wherein the data is obtained based on rotational and linear movement of the measuring device in a body frame.

[0032] Optionally, the X, Y and Z positions of the first survey location and the measuring device are determined using only motion data obtained from the inertial sensors.

[0033] Optionally, the determined distance includes a vertical distance from the measuring device to the surface, the computer processor being configured to determine the vertical distance based on the obtained distance data and the obtained motion data.

[0034] Optionally, the measuring device computer processor is configured to control the distance measurer to obtain the distance data continuously while the second motion data indicates that the measuring device is being moved from the first survey location to a second survey location. Optionally, the measuring device computer processor is configured to control the distance measurer to obtain the distance data based on an elapsed time after the second motion data indicates that the measuring device is being moved from the first survey location to a second survey location.

[0035] Optionally, the measuring device computer processor is configured to control the distance measurer to obtain the distance data based on the position of the measuring device after the second motion data indicates that the measuring device is being moved from the first survey location to a second survey location and, optionally, at specific two-dimensional positions.

[0036] Optionally, the apparatus is a handheld tool for use by a construction worker.

[0037] Optionally, the inertial sensors form an inertial measurement unit.

[0038] Optionally, the distance measurer comprises a signal transmitter and a signal receiver, wherein the signal transmitter is arranged to transmit a signal that is reflectable from the surface, and wherein the signal receiver is configured to receive the reflected signal, the distance data comprising a time of flight of the emitted and reflected signals.

[0039] Optionally, the distance measurer is configured to measure linear distance up to 10 metres or up to 5 metres.

[0040] Optionally, the distance measurer includes a laser distance measurer.

[0041] Optionally, the distance measurer provides a visible guide allowing a user of the apparatus to see a point on the surface that the distance data is being measured to.

[0042] Optionally, the visible guide includes a marker projected from the measuring device onto the surface.

[0043] Optionally, the processing device is separate to the measuring device, and wherein the measuring device comprises a transmitter configured to transmit the obtained data and the obtained distance data, and the processing device comprises a receiver configured to receive the transmitted data.

[0044] According to an aspect of the invention, there is provided a method of determining survey data relating to a feature of a land area using an apparatus comprising a measuring device and a processing device, the measuring device including a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device, and a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use, the method comprising: obtaining, by the measuring device and from the plurality of inertial sensors, first motion data representing a position of a measuring device while the measuring device is stationary at a first survey location relating to the feature; obtaining, by the measuring device and from the plurality of inertial sensors, second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location; controlling, by a distance measurer controller and based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location; determining, by the processing device, an X, Y and Z position of the first survey location based on the first motion data; determining, by the processing device, an X, Y and Z position of the measuring device based on the second motion data; determining, by the processing device, a distance from the measuring device to the ground level based on the obtained distance data; and generating, by the processing device, survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

[0045] According to an aspect of the invention, there is provided a processing device for determining survey data relating to a feature of a land area, the processing device comprising: a receiver configured to receive from a measuring device: first motion data obtained by a plurality of inertial sensors of the measuring device while the measuring device is stationary at a first survey location relating to the feature; second motion data obtained by the plurality of inertial sensors of the measuring device while the measuring device is being moved from the first survey location to a second survey location; and distance data, obtained by a distance measurer of the measuring device while the measuring device is being moved from the first survey location to the second survey location, and representing a distance from the measuring device to a ground level of the land area, the processing device further comprising a computer processor configured to: determine an X, Y and Z position of the first survey location based on the first motion data; determine an X, Y and Z position of the measuring device based on the second motion data; determine a distance from the measuring device to the ground level based on the obtained distance data; and generate survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance. According to an aspect of the invention, there is provided a method of determining survey data relating to a feature of a land, the method comprising: receiving first motion data obtained by a plurality of inertial sensors of the measuring device while the measuring device is stationary at a first survey location relating to the feature; receiving second motion data obtained by the plurality of inertial sensors of the measuring device while the measuring device is being moved from the first survey location to a second survey location; receiving distance data, obtained by a distance measurer of the measuring device while the measuring device is being moved from the first survey location to the second survey location, and representing a distance from the measuring device to a ground level of the land area; determining an X, Y and Z position of the first survey location based on the first motion data; determining an X, Y and Z position of the measuring device based on the second motion data; determining a distance from the measuring device to the ground level based on the obtained distance data; and generating survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

[0046] According to an aspect of the invention, there is provided a measuring device for obtaining survey data relating to a feature of a land area, the measuring device comprising: a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device; a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use; and a computer processor configured to: obtain first motion data from the plurality of inertial sensors while the measuring device is stationary at a first survey location relating to the feature; obtain second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location; control, based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location.

[0047] According to an aspect of the invention, there is provided a method of obtaining survey data relating to a feature of a land area using a measuring device including a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device, and a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use, the method comprising: obtaining, by the measuring device and from the plurality of inertial sensors, first motion data representing a position of a measuring device while the measuring device is stationary at a first survey location relating to the feature; obtaining, by the measuring device and from the plurality of inertial sensors, second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location; controlling, by a distance measurer controller and based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location.

[0048] According to an aspect of the invention, there is provided a computer program configured, when executed on a computer processor, to control a computer processor to undertake one or more of the steps of one or more of the methods disclosed herein.

[0049] Brief description of the drawings

[0050] Embodiments of the disclosed methods and apparatus will be described in detail below, with reference to the accompanying drawings, in which:

[0051] Figure 1 is a schematic representation of a system for determining survey data;

[0052] Figure 2 is a schematic representation of a measuring device;

[0053] Figure 3 is a schematic representation of a processing device;

[0054] Figure 4 is a plan view of a land area;

[0055] Figure 5 is a flow diagram showing a method of determining survey data; and

[0056] Figure 6 shows a construction professional holding a pole to which a measuring device and a processing device are attached.

[0057] Detailed Description

[0058] Generally, disclosed in this specification are methods and apparatus for determining a topography of a land area in a survey conducted by a construction professional. Exemplary apparatus include motion sensors, such as inertial sensors, capable of measuring linear accelerations in three orthogonal axes, and rotational velocities about those three orthogonal axes. Other motion sensors or positioning technologies may be used alternatively or in addition to inertial sensors, for example GNSS receivers. However, in specific exemplary embodiments, inertial sensors alone are used to determine position and / or orientation of a measuring device. In addition, exemplary apparatus may also include a distance measuring device, which, for example, may be configured to emit a signal in the direction of the ground when the apparatus is being carried across the land area by the construction professional. A reflected signal is received by the apparatus, providing an indication of the distance from the apparatus to the ground. The topography can be determined based on the distance to the ground and the position and / or orientation of the apparatus.

[0059] The apparatus may be configured to provide a plan of the land area by placing a measuring device on the ground at a plurality of locations to mark out a feature of the land area. At each location, the measuring device is held stationary for a period of time sufficient for the x, y and z position of the measuring device to be determined using the positioning sensors (e.g. the inertial sensors).

[0060] Figure 1 shows a schematic representation of an exemplary system 100 for determining topographic data relating to a land area. The system 100 comprises a measuring device 102 and a processing device 104. Detailed descriptions of exemplary measuring and processing devices 102, 104 are given below. Broadly, the measuring device 102 comprises one or more sensors arranged to obtain measured data representing its position and / or orientation. For example, the one or more sensors may be configured to record linear accelerations and rotational velocities and these may be used, optionally without any other positioning information, to determine the position and / or orientation of the measuring device 102. The measuring device may be placed at a number of survey locations within the land area to survey the features of the land area using the output from the sensors. In addition, the measuring device 102 includes a distance measurer configured to measure distance data representing a distance from the measuring device 102 to a surface (e.g. the ground) over which it is being carried. The distance measuring may be positioned such that it is directed towards the ground during normal use. Accordingly, the distance measurer may be configured to obtain distance data indicating a distance to the ground when the measuring device is being carried between survey locations by a construction professional. The distance data may be used by the apparatus to determine the vertical height of the ground relative to a first survey location and a second survey location as it is carried between the two.

[0061] The measuring device 102 is configured to transmit to the processing device 104 measured data representing its position and / or orientation and the distance data representing the distance from the measuring device 102 to the ground. The processing device 104 includes a processor for determining a position of each survey location and a height of the ground over which the measuring device 102 has been carried based on the measured data. The processing device 104 may be configured to present an indication of the surveyed feature(s) and the height of the ground to a construction worker. In some exemplary arrangements, the processing device may be configured to export data representing at least part of the determined surveyed feature(s) and the height of the ground. The data may, for example, be suitable for representation in CAD software, or the like.

[0062] It will be appreciated that at least part of the processing of the measured motion and distance data may be undertaken at the measuring device 102 before transmission to the processing device 104. It will also be appreciated that the processing device 104 may form part of the measuring device 102 and they may be housed within a single unit.

[0063] In exemplary arrangements, the measuring device 102 may be a hand-held or otherwise portable unit suitable for being carried by a construction worker. In exemplary arrangements, the processing device 104 may be a portable processing device, such as a mobile phone, tablet or laptop computer.

[0064] The transmission of measured data from the measuring device 102 to the processing device 104 is shown in Figure 1 as a wireless transmission 106. The wireless transmission may be a radio frequency transmission using known hardware and communications protocols, such as Bluetooth (RTM), near field communication, Wi-Fi, network based communications (e.g. the internet) or mobile telecommunications protocols. The wireless transmission 106 may also use optical transmission hardware and protocols. The transmission may be at least partially wired and, in some arrangements, could be fully wired. The processing device 104 may also transmit data to the measuring device 102 via the same, or a different, communications medium and / or protocol.

[0065] The transmission of measured motion and distance data may be substantially in real time. For example, measurements may be recorded and data representing those measurements transmitted as soon as possible thereafter, e.g. on an open communications link. In some arrangements, the transmission of data may be intermittent and / or from time-to-time. For example, the measuring device may record a plurality of measurements and store data representing the plurality of measurements for transmission at a later time. In such arrangements, the transmission may be triggered manually, e.g. after all measured data has been collected, or may be triggered by the measuring device 102 detecting an open communication channel (either direct or indirect) to the processing device 104. Figure 2 shows a schematic representation of a measuring device 102, which may be the measuring device 102 in Figure 1. The measuring device 102 comprises a transmitter 202 and, optionally, a receiver 204. The transmitter 202 and receiver 204 may be in data communication with other entities, such as the processing device 104 or servers and / or functions in a telecommunications network, and are configured to transmit and receive data accordingly.

[0066] The measuring device 102 further comprises a memory 206 and a processor 208. The memory 206 may comprise a non-volatile memory and / or a volatile memory. The memory 206 may have a computer program 210 stored therein. The computer program 210 may be configured to undertake methods disclosed herein. The computer program 210 may be loaded in the memory 206 from a non-transitory computer readable medium 212, on which the computer program is stored. The measuring device 102 may also comprise motion sensors 214 (e.g. inertial sensors). In specific arrangements, the motion sensors 214 may consist of only inertial sensors. In specific arrangements, only inertial sensors are used to determine position and / or orientation of the measuring device. The inertial sensors may consist of MEMs sensors. The measuring device 102 may also include a distance measurer 216 arranged to determine a linear distance between the measuring device 102 and a surface. The distance measurer may be a laser distance measurer (LDM) or a LiDAR sensor. The processor 208 is configured to undertake one or more of the functions necessary for operation of one or more of the elements of the measuring device 102.

[0067] The inertial sensors 214 may comprise accelerometers and / or rate gyros. The inertial sensors 214 may be arranged to measure acceleration and / or rotational velocity of the measuring device 102 in three orthogonal axes, typically identified as x-axis, y-axis and z-axis. The accelerations and rotational velocities may be recorded in a body frame (i.e., a frame fixed in relation to the measuring device 102 and defined by the x, y and z axes) and converted to any other reference frame (e.g. a local reference frame based on the land area or a construction site) using well known techniques. The inertial sensors 214 may form part of an Inertial Measurement Unit (IMU) housed within the measuring device 102. The inertial sensors 214 may incorporate micro-electro-mechanical systems (MEMS) technology.

[0068] Throughout this document, inertial sensors are referred to, although it should be understood that other motion or positioning sensors may be employed as an alternative or in addition to the inertial sensors. Such motion or positioning sensors include any sensor that is able to detect rotational and / or linear movement of the measuring device 102. These may include, as examples only, sensors using technology relating to GNSS, doppler, cellular positioning, wi-fi positioning, cameras, LiDAR etc. In exemplary arrangements, any motion or positioning sensors that use a ‘dead reckoning’ form of positioning and / or orientation may be used.

[0069] The distance measurer 216 may comprise a signal emitter and a signal receiver. The emitter may be configured to emit a signal that is reflectable off a surface to which a linear distance is to be measured. The signal receiver may be arranged to receive a signal reflected from the surface. In exemplary arrangements, the signal emitter may be arranged to emit a laser based signal. The distance measurer 216 may comprise a laser distance measurer. The distance measurer 216 may comprise a transmitter configured to emit an EM and / or sonar based signal. The transmitter and / or receiver of the distance measurer may be configured to measure linear distance up to one of the following: 50 metres, 25 metres, 10 metres, 5 metres or 2 metres. That is, the power of the transmitter and / or the sensitivity of the receiver may be configured to measure the above mentioned linear distances. For example, the power of the transmitter and / or the sensitivity of the receiver may be configured to measure linear distance up to 2 metres, 5 metres or 10 metres.

[0070] The measuring device 102 may be a portable and in some cases handheld device. In exemplary arrangements, the measuring device and the processing device 104 may be combined and may together be portable and / or handheld. In specific arrangements, the measuring device 102 and / or the processing device 104 may be a handheld tool suitable for use by a construction worker.

[0071] The processor 208 may include a distance measurer controller 218 that is arranged to control when the distance measurer 216 emits a signal for measuring the distance between the measuring device 102 and the ground. The processor 208 may further include a distance measurer timer 220 that is arranged to record the time of flight of the emitted and reflected signals emitted by the distance measurer 216. The processor 208 may further include a synchroniser 222 that is arranged to synchronise data relating to the distance between the measuring device 102 and the ground that has been determined from the distance measurer 216 with data recorded by the motion sensors 214. The processor 208 may further include a position and orientation determiner 224 that is arranged to determine position and orientation of the measuring device based on motion data recorded by the motion sensors 214.

[0072] Each of the transmitter 202 and receiver 204, memory 206, processor 208, inertial sensors 214 and distance measurer 216 is in data communication with the other features of the measuring device 102. The measuring device 102 can be implemented as a combination of hardware and software. In particular, software may be configured to run on the processor 208. The memory 206 stores the various programs / executable files that are implemented by the processor 208, and also provides a storage unit for any required data.

[0073] Figure 3 shows a schematic representation of a processing device 104, which may be the processing device 104 in Figure 1. The processing device 104 comprises a receiver 304 and optionally a transmitter 302. The transmitter 302 and receiver 304 may be in data communication with other entities, such as measuring device 102 or servers and / or functions in a telecommunications network, and are configured to transmit and receive data accordingly.

[0074] The processing device 104 further comprises a memory 306 and a processor 308. The memory 306 may comprise a non-volatile memory and / or a volatile memory. The memory 306 may have a computer program 310 stored therein. The computer program 310 may be configured to undertake the methods disclosed herein. The computer program 310 may be loaded in the memory 306 from a non-transitory computer readable medium 312, on which the computer program 310 is stored. The processor 308 is configured to undertake, the functions of a position and orientation processor 314, a distance processor 316 and a surface generator 318, as set out below. The processing device 104 also optionally comprises a display 320 and a user interface 322.

[0075] Each of the transmitter 302 and receiver 304, memory 306, processor 308, display 320 and user interface 322 is in data communication with the other features of the processing device 104. The processing device 104 can be implemented as a combination of hardware and software. In particular, the position and orientation processor 314, distance processor 316 and surface generator 318 may be implemented as software configured to run on the processor 308. The memory 306 stores various programs / executable files that are implemented by the processor 308, and also provides a storage unit for any required data. The programs / executable files stored in the memory 306, and implemented by the processor 308, can include the position and orientation processor 314, distance processor 316 and surface generator 318, but are not limited to such.

[0076] Figure 4 shows a plan view of a land area 400. The land area 400 includes a driveway 402 to a property. The driveway 402 extends from a road 404. The driveway 402 includes an outer boundary 406 and a central ‘island’ area 408. Although not visible in plan view, the elevation of the driveway 402 rises from the road 404 up to the frontage of a building 410. Figure 5 shows an exemplary flow chart of a method of determining a topography of a surface, in this case the ground of the driveway 400. A construction professional may use the apparatus described herein to survey the driveway 400. This may be done by moving the apparatus to a plurality of survey locations 412 around the outer boundary 406, and the central island 408. A few of the survey locations are shown by dots around a part of the boundary of the driveway as exemplary survey locations although it will be appreciated that others may be added. The 3-dimensional position of the measuring device 102 may be determined at each survey location. In addition, the distance measurer 216 may determine a distance from the measuring device 102 to the ground during a time when the measuring device 102 is being moved between survey locations 412. This allows the feature of the driveway and the island to be surveyed with increased accuracy and resolution.

[0077] In addition, if internal features of the driveway 400 are to be surveyed, the construction professional may also move the apparatus across the internal area of the driveway 400. This may be done along ‘survey lines’ that may be parallel and span the internal area. Also, further survey locations 412 may be used that are located in the internal area of the driveway.

[0078] At step 500, a survey of the driveway 400 is begun. This may be initiated by the construction professional, for example, by interacting with a user interface on either of the measuring device 102 or the processing device 104. In exemplary arrangements, the processing device 104 may comprise a mobile device having an application running thereon. The application may display a GUI to the construction professional, who may interact with the GUI to initiate the survey.

[0079] At step 502, the measuring device 102 is moved to a first survey location 412. Motion data is obtained. This may be done using the motion sensors 214 of the measuring device 102. As mentioned above, the motion sensors 214 may be inertial sensors configured to measure motion data comprising angular velocity and linear accelerations in the body frame of the measuring device 102 and, in some arrangements, only such inertial sensors are used to determine position and orientation of the measuring device 102 at the first survey location. The synchroniser 222 may be configured to time stamp each measurement making up the obtained motion data.

[0080] At step 504, the measuring device 102 is moved to the next survey location 412, in this case along the boundary of the driveway 400. While the measuring device 102 is being carried to the next survey location 412, the distance measurer controller 218 controls the distance measurer 216 to obtain distance data. The distance data may be obtained using the distance measurer 216 of the measuring device 102. The distance measurer controller 218 may determine that the measuring device is being moved between survey locations 412 based on data from the motion sensors. Specifically, the distance measurer controller 218 may determine that the measuring device is being moved between survey locations 412 after the measuring device 102 has been stationary at a survey location for a period of time.

[0081] In specific arrangements, the distance measurer 216 may be configured to emit, from the signal emitter, a signal that is reflectable off a surface. For example, the distance measurer 216 may emit an electromagnetic signal, a sonic signal or a light based signal. In an exemplary arrangement that is used in this description, the distance measurer 216 may include a laser distance measurer (LDM).

[0082] The LDM emits a laser that is reflected off of the ground and received by the signal receiver. The distance measurer timer 220 measures the time of flight of the light of the laser, which is indicative of the distance between the measuring device 102 and the ground of the driveway 400.

[0083] As will be explained, the distance measurer controller 218 may be configured to control the distance measurer 216 to obtain the distance data in a number of ways and at a number of different times or two-dimensional (i.e. X and Y) locations. In one exemplary arrangement, the distance measurer controller 218 controls the distance measurer 216 to obtain the distance data continuously while the measuring device is being carried between survey locations. In alternative arrangements, distance data may be obtained at regular time or position intervals.

[0084] At step 506, the obtained motion data and the obtained distance data may be synchronised. This step is optional and may be undertaken by the synchroniser 222. In exemplary arrangements, the synchroniser 222 may be configured to time stamp the distance data. This may be done using a common clock to that used to time stamp the motion data.

[0085] In some arrangements, the synchroniser 222 may trigger the distance measurer controller 218 to obtain distance data at a time that coincides with a time when motion data is obtained that is closest to the time or location specified by the distance measurer controller 218 (mentioned above). In this case, the distance data is, in effect, stamped with the same time stamp as the corresponding motion data by virtue of the time that the distance data is obtained.

[0086] Motion data, for example from an IMU, may be obtained at regular intervals and time stamped accordingly. This may be done continuously over a specific time period, such as the time period between the start and end of the survey or a shorter time period defined during the survey. The motion data may therefore be considered to be obtained continuously during a time period.

[0087] In some arrangements, the distance measurer controller 218 may control the distance measurer 216 to obtain a distance measure at regular intervals that are time stamped accordingly. This may be done continuously over a specific time period, such as the time period between the start and end of the survey or a shorter time period defined during the survey. The distance data may therefore be considered to be obtained continuously during a time period. The distance data may be obtained at a time coincident with a time stamp of the motion data, e.g. every motion data time stamp, every second motion data time stamp, every third motion data time stamp etc. It will be understood that any number of motion data time stamps may be skipped over in this way. In particular, the motion data may be collected at between 50 Hz to 1000Hz or similar and the distance data may be collected at less than 10 Hz or even less than 5 Hz.

[0088] In other arrangements, the distance measurer controller 218 may control the distance measurer 216 to obtain a distance measure at intervals independent of the motion data time stamps. In such arrangements, the synchroniser 222 is configured to time stamp the distance data at the time a distance measurement is initiated. This may be done using a common clock with the motion data time stamps.

[0089] In one example shown in Figure 6, the measuring device 102 may be positioned at one end of a pole 600 and the processing device 104 may be positioned at an opposite end of the pole 600. A construction professional 602 may conveniently hold the pole 600 such that the measuring device 102 is close to the ground and the processing device 104 is uppermost.

[0090] In such arrangements, the construction professional may begin a survey by placing the measuring device 102 on the ground at a survey location 412 on the outer boundary 406 of the driveway 400. The pole 600 may then be moved such that the measuring device 102 is held slightly off the ground and traces the outer boundary 406. Motion data may be obtained continuously during this movement such that the position and / or orientation of the measuring device 102 may be determined. This allows the line of the outer boundary 406 to be traced as part of the survey. It is noted that, to improve accuracy of the motion data, the measuring device 102 may be placed on the ground at the survey locations 412 around the outer boundary 406. The measuring device 102 may be positioned on the pole 600 such that the distance measurer 216 is able to measure a distance between the measuring device 102 and the ground. For example, in embodiments in which the distance measurer 216 emits and receives a signal to measure the distance, the distance measurer 216 may be positioned such that it is facing in a direction opposite to the direction in which the pole 600 extends. During use, the distance measurer 216 is therefore directed at the ground.

[0091] The distance measurer controller 218 may control the distance measurer 216 to obtain the distance data continuously as the measuring device 102 traces the outer boundary 406 between survey locations 412. Alternatively, the distance measurer controller 218 may control the distance measurer 216 to obtain the distance data based on an elapsed time. For example, the distance data may be obtained at specific times during the survey, e.g. periodically after a set time period has elapsed. In one example, the time period may begin when the measuring device 102 is moved from a survey location.

[0092] The distance measurer controller 218 may control the distance measurer 216 to obtain the distance data based on a position of the measuring device 102. For example, distance data may be obtained at specific distances during the movement of the measuring device as it traces the outer boundary 406, e.g. periodically after the measuring device has travelled a set distance from a survey location 412. In arrangements in which the distance data is obtained based on a position of the measuring device, the position and orientation determiner 224 of the measuring device may be arranged to determine the position of the measuring device 102 based on the obtained motion data. Alternatively, the position of the measuring device 102 may be determined by the processing device 104 (see below) and transmitted to the measuring device 102 for use by the distance measurer controller 218.

[0093] As discussed above, the synchroniser 222 synchronises the motion data and the distance data as necessary.

[0094] It is noted, for the avoidance of doubt, that the pole 600 is not required for implementation of the invention but is an aid for the construction professional 602. The measuring device 102 may be carried or otherwise transported around the outer boundary 406.

[0095] At step 508, the position and orientation determiner 314 of the processing device 104 determines a position and / or orientation of the measuring device 102 based on the obtained motion data. This may be done using methods known to the skilled person. At step 510, the distance processor 316 determines the distance to the ground or other surface from the measuring device 102 based on the obtained distance data. This may be done using methods known to the skilled person.

[0096] In arrangements where the measuring device 102 and the processing device 104 are separate units, the transmitter 202 of the measuring device 102 may transmit the obtained motion data and distance data, which is then received by the receiver 304 of the processing device 104.

[0097] At step 512, survey data (in this case the position of the outer boundary 406 and the height of the ground between survey locations is determined by the surface generator 318 based on the determined position, and optionally orientation, of the measuring device 102 and the determined distance to the ground from the measuring device 102. The survey data may include X, Y and Z coordinates of a plurality of points along the outer boundary 406. The X, Y and Z coordinates may be in a reference frame that is local to the area of the survey - a local reference frame. In the example used in this description, the X and Y axes provide a plane that is locally level, and the Z axis is orthogonal to that plane and aligned with a vertical direction.

[0098] The survey data includes the X, Y and Z position of the survey locations 412 at which the measuring device 102 was held stationary. In addition, the survey data may include the X, Y and Z position of the outer boundary 406 as the line of the boundary is traced between survey locations 412.

[0099] In one arrangement, the position of the measuring device 102 is determined in the local reference frame (based on body frame measurements), providing an X, Y, Z position for the measuring device 102. The survey data may be obtained by determining the X and Y position and offsetting in the Z axis of the local reference frame by the determined distance. The X and Y positions of the topographic data may be determined to be identical to those of the measuring device 102. This arrangement assumes that the distance measured by the distance measurer 216 is equal to the vertical distance from the measuring device 102 to the ground, which may be a valid assumption in a number of use cases.

[0100] In other arrangements, a vertical distance from the measuring device 102 to the ground may be determined based on the motion data and the distance data. For example, the orientation of the measuring device 102 may be determined, which allows the determination of an angle from the Z axis of the local frame at which the distance data was measured. The determined angle may be used in conjunction with the distance data to determine vertical distance from the measuring device 102 in ways that are well known to the skilled person.

[0101] After the outer boundary 406 has been traced, the process may be repeated for the boundary of the central island 408. If survey data is required for areas between the outer boundary 406 and the island 408, the construction professional 602 may also survey those areas by moving the measuring device 102 across them. This may be done in a uniform pattern, e.g. using parallel survey lines.

[0102] The measuring device may include a guide for allowing the construction professional 602 to direct the distance measurer 216 at the correct point on the ground (or other surface). In exemplary arrangements, the guide may be projected from the measuring device 102 onto the ground, for example using visible light. When the distance measurer 216 includes an LDM, the emitted laser may be used as the guide.

[0103] In addition, an indication of the orientation of the measuring device with respect to level in the local reference frame may be provided to the construction professional 602. The orientation of the measuring device for this indication may use the motion sensors 214 or may use a separate level sensor.

[0104] The methods and apparatus described herein provide numerous technical benefits over known practices. For example, by understanding the relief of the ground in between survey locations, the survey of the feature has greater accuracy and resolution. Previous apparatus were only able to obtain data for a feature when a measuring device is placed at the survey location and held there for a period of time. Height data between survey locations is estimated.

[0105] A computer program may be configured to provide any of the above described methods. The computer program may be provided on a computer readable medium. The computer program may be a computer program product. The product may comprise a non-transitory computer usable storage medium. The computer program product may have computer-readable program code embodied in the medium configured to perform the method. The computer program product may be configured to cause at least one processor to perform some or all of the method.

[0106] Various methods and apparatus are described herein with reference to block diagrams or flowchart illustrations of computer-implemented methods, apparatus (systems and / or devices) and / or computer program products. It is understood that a block of the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can be implemented by computer program instructions that are performed by one or more computer circuits. These computer program instructions may be provided to a processor circuit of a general purpose computer circuit, special purpose computer circuit, and / or other programmable data processing circuit to produce a machine, such that the instructions, which execute via the processor of the computer and / or other programmable data processing apparatus, transform and control transistors, values stored in memory locations, and other hardware components within such circuitry to implement the functions / acts specified in the block diagrams and / or flowchart block or blocks, and thereby create means (functionality) and / or structure for implementing the functions / acts specified in the block diagrams and / or flowchart block(s).

[0107] Computer program instructions may also be stored in a computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the functions / acts specified in the block diagrams and / or flowchart block or blocks.

[0108] A tangible, non-transitory computer-readable medium may include an electronic, magnetic, optical, electromagnetic, or semiconductor data storage system, apparatus, or device. More specific examples of the computer-readable medium would include the following: a portable computer diskette, a random access memory (RAM) circuit, a read-only memory (ROM) circuit, an erasable programmable read-only memory (EPROM or Flash memory) circuit, a portable compact disc read-only memory (CD-ROM), and a portable digital video disc readonly memory (DVD / Blu-ray).

[0109] The computer program instructions may also be loaded onto a computer and / or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer and / or other programmable apparatus to produce a computer- implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions / acts specified in the block diagrams and / or flowchart block or blocks.

[0110] Accordingly, the invention may be embodied in hardware and / or in software (including firmware, resident software, micro-code, etc.) that runs on a processor, which may collectively be referred to as “circuitry,” “a module” or variants thereof. It should also be noted that in some alternate implementations, the functions / acts noted in the blocks may occur out of the order noted in the flowcharts. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality / acts involved. Moreover, the functionality of a given block of the flowcharts and / or block diagrams may be separated into multiple blocks and / or the functionality of two or more blocks of the flowcharts and / or block diagrams may be at least partially integrated. Finally, other blocks may be added / inserted between the blocks that are illustrated. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed systems and methods. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed systems and methods. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.

Claims

CLAIMS1 . An apparatus for determining survey data relating to a feature of a land area, the apparatus comprising: a measuring device including: a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device; a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use; and a measuring device computer processor configured to: obtain first motion data from the plurality of inertial sensors while the measuring device is stationary at a first survey location relating to the feature; obtain second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location; control, based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location, the apparatus further comprising a processing device comprising a processing device computer processor configured to: determine an X, Y and Z position of the first survey location based on the first motion data; determine an X, Y and Z position of the measuring device based on the second motion data; determine a distance from the measuring device to the ground level based on the obtained distance data; and generate survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

2. The apparatus according to claim 1 , wherein the motion data further represents orientation of the measuring device, and optionally wherein the data is obtained based on rotational and linear movement of the measuring device in a body frame.

3. The apparatus according to claim 1 or 2, wherein the X, Y and Z positions of the first survey location and the measuring device are determined using only motion data obtained from the inertial sensors.

4. The apparatus according to any preceding claim, wherein the determined distance includes a vertical distance from the measuring device to the surface, the computer processor being configured to determine the vertical distance based on the obtained distance data and the obtained motion data.

5. The apparatus according to any preceding claim, wherein the measuring device computer processor is configured to control the distance measurer to obtain the distance data continuously while the second motion data indicates that the measuring device is being moved from the first survey location to a second survey location.

6. The apparatus according to any preceding claim, wherein the measuring device computer processor is configured to control the distance measurer to obtain the distance data based on an elapsed time after the second motion data indicates that the measuring device is being moved from the first survey location to a second survey location.

7. The apparatus according to claim 5 or 6, wherein the measuring device computer processor is configured to control the distance measurer to obtain the distance data based on the position of the measuring device after the second motion data indicates that the measuring device is being moved from the first survey location to a second survey location and, optionally, at specific two-dimensional positions.

8. The apparatus according to any preceding claim, wherein the apparatus is a handheld tool for use by a construction worker.

9. The apparatus according to any preceding claim, wherein the inertial sensors form an inertial measurement unit.

10. The apparatus according to any preceding claim, wherein the distance measurer comprises a signal transmitter and a signal receiver, wherein the signal transmitter is arranged to transmit a signal that is reflectable from the surface, and wherein the signal receiver is configured to receive the reflected signal, the distance data comprising a time of flight of the emitted and reflected signals.1 1. The apparatus according to any preceding claim, wherein the distance measurer is configured to measure linear distance up to 10 metres or up to 5 metres.

12. The apparatus according to any preceding claim, wherein the distance measurer includes a laser distance measurer.

13. The apparatus according to any preceding claim, wherein the distance measurer provides a visible guide allowing a user of the apparatus to see a point on the surface that the distance data is being measured to.

14. The apparatus according to any preceding claim, wherein the visible guide includes a marker projected from the measuring device onto the surface.

15. The apparatus according to any preceding claim, wherein the processing device is separate to the measuring device, and wherein the measuring device comprises a transmitter configured to transmit the obtained data and the obtained distance data, and the processing device comprises a receiver configured to receive the transmitted data.

16. A method of determining survey data relating to a feature of a land area using an apparatus comprising a measuring device and a processing device, the measuring device including a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device, and a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use, the method comprising: obtaining, by the measuring device and from the plurality of inertial sensors, first motion data representing a position of a measuring device while the measuring device is stationary at a first survey location relating to the feature; obtaining, by the measuring device and from the plurality of inertial sensors, second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location controlling, by a distance measurer controller and based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location;determining, by the processing device, an X, Y and Z position of the first survey location based on the first motion data; determining, by the processing device, an X, Y and Z position of the measuring device based on the second motion data; determining, by the processing device, a distance from the measuring device to the ground level based on the obtained distance data; and generating, by the processing device, survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

17. A computer program configured, when executed on a computer processor, to control a computer processor to undertake one or more of the steps of the method of claim 16.

18. A processing device for determining survey data relating to a feature of a land area, the processing device comprising: a receiver configured to receive from a measuring device: first motion data obtained by a plurality of inertial sensors of the measuring device while the measuring device is stationary at a first survey location relating to the feature; second motion data obtained by the plurality of inertial sensors of the measuring device while the measuring device is being moved from the first survey location to a second survey location; and distance data, obtained by a distance measurer of the measuring device while the measuring device is being moved from the first survey location to the second survey location, and representing a distance from the measuring device to a ground level of the land area, the processing device further comprising a computer processor configured to: determine an X, Y and Z position of the first survey location based on the first motion data; determine an X, Y and Z position of the measuring device based on the second motion data; determine a distance from the measuring device to the ground level based on the obtained distance data; and generate survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

19. A method of determining survey data relating to a feature of a land, the method comprising: receiving first motion data obtained by a plurality of inertial sensors of the measuring device while the measuring device is stationary at a first survey location relating to the feature; receiving second motion data obtained by the plurality of inertial sensors of the measuring device while the measuring device is being moved from the first survey location to a second survey location receiving distance data, obtained by a distance measurer of the measuring device while the measuring device is being moved from the first survey location to the second survey location, and representing a distance from the measuring device to a ground level of the land area; determining an X, Y and Z position of the first survey location based on the first motion data; determining an X, Y and Z position of the measuring device based on the second motion data; determining a distance from the measuring device to the ground level based on the obtained distance data; and generating survey data for the feature based on the determined X, Y and Z position of the first survey location, the determined X, Y and Z position of the measuring device and the determined distance.

20. A computer program configured, when executed on a computer processor, to control a computer processor to undertake one or more of the steps of the method of claim 19.21 . A measuring device for obtaining survey data relating to a feature of a land area, the measuring device comprising: a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device; a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use; and a computer processor configured to: obtain first motion data from the plurality of inertial sensors while the measuring device is stationary at a first survey location relating to the feature;obtain second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location; control, based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location.

22. A method of obtaining survey data relating to a feature of a land area using a measuring device including a plurality of inertial sensors configured to obtain motion data representing position of the measuring device based on linear accelerations and rotational velocities of the measuring device, and a distance measurer configured to obtain distance data representing a distance from the measuring device to a ground level of the land area during use, the method comprising: obtaining, by the measuring device and from the plurality of inertial sensors, first motion data representing a position of a measuring device while the measuring device is stationary at a first survey location relating to the feature; obtaining, by the measuring device and from the plurality of inertial sensors, second motion data from the plurality of inertial sensors indicating that the measuring device is being moved from the first survey location to a second survey location controlling, by a distance measurer controller and based on the second motion data, the distance measurer to obtain distance data at one or more times while the measuring device is being moved from the first survey location to the second survey location.

23. A computer program configured, when executed on a computer processor, to control a computer processor to undertake one or more of the steps of the method of claim 22.

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