Devices and methods for aligning survey measurements

Abstract

Methods and apparatus for aligning sets of survey measurements The sets of survey measurements are recorded using a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device. During a survey period: the measuring device is positioned at a plurality of locations; records motion data; and determines, using dead reckoning and based on the motion data, a set of survey measurements, each survey measurement comprising a position and orientation of the measuring device at one of the plurality of locations. During a further survey period: the or a further measuring device is positioned at one or more survey features determined based on the set of survey measurements; records alignment motion data while the or the further measuring device is at the one or more survey features; determines an alignment position and an alignment direction based on the alignment motion data. The or the further measuring device is positioned at a further plurality of locations. The or the further measuring device records further motion data; and determines, using dead reckoning and based on the further motion data, a set of further survey measurements, each further survey measurement comprising a position and orientation of the measuring device at one of the further plurality of locations; and aligns the set of survey measurements with the set of further survey measurements based on the alignment position and the alignment direction.

Description

[0001] DEVICES AND METHODS FOR ALIGNING

[0002] SURVEY MEASUREMENTS

[0003] Technical field

[0004] The invention relates to methods and apparatus for determining a position of a survey measurement in a local coordinate system and / or relative to survey positions previously recorded. In particular, the invention may relate to, but need not be limited to, aligning sets of survey measurements of the built and / or natural environments relative to each other.

[0005] Background

[0006] For many applications, it is necessary to have accurate survey data relating to the built and / or natural environments. In order to produce such survey data, the dimensions and alignment of a number of features of the built and / or natural environments (survey features) must be measured. It is also desirable for each feature to be aligned relative to other features.

[0007] Traditional techniques for measuring the dimensions of features include the use of tape measures or other linear distance measuring devices. However, this is time consuming, can often require the involvement of two construction professionals and is prone to significant error. In addition, measuring the dimensions of the features does not provide any information as to their relative alignment. It is possible to measure linear distances between features, but this adds further time and complication to a survey.

[0008] It is known to use survey equipment, such as a total station, to provide a survey. A total station allows the dimensions of a number of features to be measured and provides their relative orientations or alignments. However, for many applications, a total station is not an appropriate tool to conduct a survey. A total station is an expensive tool requiring skilled operation and for many applications would be overkill.

[0009] There is a need for an accurate, efficient and cost effective method for surveying features of the built and natural environments and recording their relative positions and alignments in a local coordinate system.Summary

[0010] Methods and apparatus disclosed herein are directed to solving one or more problems in the prior art, including those disclosed herein. In particular, it has been appreciated by the inventors that sets of measurements may be undertaken during a survey at different times. The sets of measurements may each be ‘closed off’ in that the particular set is completed. This may be done, for example, to reduce or minimise measurement error, because each set of measurements is to be placed in a separate ‘layer’ and manipulated separately in CAD software, or because there is a natural break in the working day, such as lunch or the end of the day. It is beneficial for such sets of measurements to be aligned with each other.

[0011] According to the invention in an aspect, there is provided a method of aligning first and second sets of survey measurements, wherein the first and second sets of survey measurements are recorded using a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device, the method comprising: during a first survey period: positioning the measuring device at a first plurality of locations; recording first motion data at the measuring device; and determining, using dead reckoning and based on the first motion data, a first set of survey measurements, each of the survey measurements in the first set comprising a position and orientation of the measuring device at one of the plurality of first locations; during a second survey period: positioning the or a further measuring device at one or more survey features determined based on the first set of survey measurements; recording alignment motion data while the or the further measuring device is at the one or more survey features; determining an alignment position and an alignment direction based on the alignment motion data; positioning the or the further measuring device at a second plurality of locations; recording second motion data of the or the further measuring device; and determining, using dead reckoning and based on the second motion data, a second set of survey measurements, each of the survey measurements in the second set comprising a position and orientation of the measuring device at one of the second plurality of locations; and aligning the first set of survey measurements with the second set of survey measurements based on the alignment position and the alignment direction.

[0012] According to the invention in an aspect, there is provided a method of aligning sets of survey measurements, wherein the sets of survey measurements are recorded using a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device, the method comprising: during a survey period: positioning the measuring device at a plurality of locations; recording motion data at the measuring device; and determining, using dead reckoning and based on the motion data, aset of survey measurements, each survey measurement comprising a position and orientation of the measuring device at one of the plurality of locations; during a further survey period: positioning the or a further measuring device at one or more survey features determined based on the set of survey measurements; recording alignment motion data while the or the further measuring device is at the one or more survey features; determining an alignment position and an alignment direction based on the alignment motion data; positioning the or the further measuring device at a further plurality of locations; recording further motion data of the or the further measuring device; and determining, using dead reckoning and based on the further motion data, a set of further survey measurements, each further survey measurement comprising a position and orientation of the or the further measuring device at one of the further plurality of locations; and aligning the set of survey measurements with the set of further survey measurements based on the alignment position and the alignment direction.

[0013] Optionally, the one or more of the survey features comprises a survey feature having a known position and orientation, and wherein determining the alignment position comprises determining a position of the measuring device at the survey feature, and determining the alignment direction comprises determining an orientation of the measuring device at the survey feature.

[0014] Optionally, the one or more of the survey features comprise a first survey feature having a known position, and a second survey feature having a known position, wherein determining the alignment position comprises determining a position of the measuring device at the first survey feature, and wherein determining the alignment direction comprises determining a position of the second survey feature, and determining a direction between the position of the measuring device at the first survey feature and the position of the measuring device at the second survey feature.

[0015] Optionally, determining the alignment position further comprises mitigating an error in the determination of the position of the measuring device at the first survey feature based on the position of the measuring device at the second survey feature.

[0016] Optionally, the first survey feature and / or the second survey feature has a known orientation, and wherein determining the alignment direction comprises mitigating an error in the determination of the direction between the position of the measuring device at the first survey feature and the position of the measuring device at the second survey feature based on an orientation of the measuring device at the first and / or second survey feature.Optionally, the one or more survey features comprises at least one additional survey feature having a known position and / or orientation, and wherein determining the alignment position and / or alignment direction comprises determining a position and / or orientation of the measuring device at the at least one additional survey feature.

[0017] Optionally, the one or more of the survey features comprises a first survey feature having a known orientation, and a second survey feature having a known orientation, and wherein the orientations of the first and second survey features are transverse to each other, wherein determining the alignment position comprises determining an intersection of the orientations of the measuring device at the first and second survey features, and wherein the alignment direction is determined to be the orientation of the measuring device at the first or second survey features.

[0018] Optionally, the first and second survey features form a corner defined by surfaces of room or building.

[0019] Optionally, the first survey feature comprises a wall of a room or building, and wherein the second survey feature comprises an internal surface of an opening in the wall of the room or building.

[0020] Optionally, the method further comprises defining a coordinate system based on the alignment position and alignment direction, the alignment direction defining a first axis, the alignment position defining an origin, and a second axis being defined transverse to the first axis.

[0021] Optionally, the method further comprises determining the set of further survey measurements in the coordinate system

[0022] Optionally, at least one of the one or more survey features is an end of a wall. An end of a wall may include any internal or external wall corner, i.e. a 90 degree or 270 degree corner. Accordingly, the end of a wall may include a corner of an opening in the wall, such as a door, window or recess.

[0023] Optionally, the motion data comprises only inertial sensor data.

[0024] According to the invention in an aspect, there is provided a method of aligning first and second sets of survey measurements, the method comprising: receiving first motion data recorded during a first survey period using a measurement device comprising a plurality of sensorsconfigured to obtain motion data, including linear and rotational motion of the measuring device; determining, using dead reckoning and based on the first motion data, a first set of survey measurements, each of the survey measurements in the first set comprising a position and orientation of the measuring device at one of a first plurality of locations; receiving alignment motion data recorded during a second survey period using the or a further measurement device, wherein the alignment motion data has been recorded while the or the further measuring device was positioned at one or more survey features determined based on the first set of survey measurements; determining an alignment position and an alignment direction based on the alignment motion data; receiving second motion data recorded while the or the further measuring device was positioned at a second plurality of locations; determining, using dead reckoning and based on the second motion data, a second set of survey measurements, each of the survey measurements in the second set comprising a position and orientation of the measuring device at one of the second plurality of locations; and aligning the first set of survey measurements with the set of second set of survey measurements based on the alignment position and the alignment direction.

[0025] According to the invention in an aspect, there is provided a method of aligning sets of survey measurements, the method comprising: receiving motion data recorded during a survey period using a measurement device comprising a plurality of sensors configured to obtain motion data, including linear and rotational motion of the measuring device; determining, using dead reckoning and based on the motion data, a set of survey measurements, each survey measurement comprising a position and orientation of the measuring device at one of the plurality of locations; receiving second motion data recorded during a further survey period using the or a further measurement device, wherein the second motion data comprises: alignment motion data recorded while the or the further measuring device was positioned at one or more survey features determined based on the set of survey measurements; and further motion data recorded while the or the further measuring device was positioned at a further plurality of locations; determining an alignment position and an alignment direction based on the alignment motion data; determining, using dead reckoning and based on the further motion data, a set of further survey measurements, each further survey measurement comprising a position and orientation of the measuring device at one of the further plurality of locations; and aligning the set of survey measurements with the set of further survey measurements based on the alignment position and the alignment direction.

[0026] According to the invention in an aspect, there is provided an apparatus for aligning first and second sets of survey measurements, the apparatus comprising one or more computer processors configured to: receive first motion data recorded during a first survey period usinga measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device; determine, using dead reckoning and based on the first motion data, a first set of survey measurements, each survey measurement in the first set comprising a position and orientation of the measuring device at one of a plurality of first locations; receive alignment motion data recorded during a second survey period using the or a further measurement device, wherein the alignment motion data has been recorded while the or the further measuring device was positioned at one or more survey features determined based on the first set of survey measurements; determining an alignment position and an alignment direction based on the alignment motion data; receive second motion data recorded while the or the further measuring device was positioned at a second plurality of locations; determine, using dead reckoning and based on the second motion data, a set of second survey measurements, each survey measurement in the second set comprising a position and orientation of the measuring device at one of the second plurality of locations; and align the first set of survey measurements with the second set of survey measurements based on the alignment position and the alignment direction.

[0027] According to the invention in an aspect, there is provided an apparatus for aligning sets of survey measurements, the apparatus comprising one or more computer processors configured to: receive motion data recorded during a survey period using a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device; determine, using dead reckoning and based on the motion data, a set of survey measurements, each survey measurement comprising a position and orientation of the measuring device at one of the plurality of locations; receive second motion data recorded during a further survey period using the or a further measurement device, wherein the second motion data comprises: alignment motion data recorded while the or the further measuring device was positioned at one or more survey features determined based on the set of survey measurements; and further motion data recorded while the or the further measuring device was positioned at a further plurality of locations; determining an alignment position and an alignment direction based on the alignment motion data; determine, using dead reckoning and based on the further motion data, a set of further survey measurements, each further survey measurement comprising a position and orientation of the measuring device at one of the further plurality of locations; and align the set of survey measurements with the set of further survey measurements based on the alignment position and the alignment direction.

[0028] According to the invention in an aspect, there is provided a system for aligning sets of survey measurements, the system comprising: a measurement device comprising a plurality ofsensors configured to obtain motion data including linear and rotational motion of the measuring device, and configured to record survey measurements, and configured, during a survey period, to: record first motion data while the measuring device is positioned at a plurality of first locations; and a processing device, configured to: determine, using dead reckoning and based on the first motion data, a first set of survey measurements, each survey measurement in the first set comprising a position and orientation of the measuring device at one of the first plurality of locations; wherein the or a further measuring device is further configured, during a second survey period, to: record alignment motion data while the or the further measuring device is positioned at one or more survey features determined based on the first set of survey measurements; and record second motion data while the or the further measuring device is positioned at a second plurality of locations; and wherein the processing device is further configured to: determine an alignment position and an alignment direction based on the alignment motion data; and determine, using dead reckoning and based on the second motion data, a second set of survey measurements, each survey measurement in the second set comprising a position and orientation of the or the further measuring device at one of the second plurality of locations; and align the first set of survey measurements with the second set of survey measurements based on the alignment position and the alignment direction.

[0029] According to the invention in an aspect, there is provided a system for aligning sets of survey measurements, the system comprising: a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device, and configured to record survey measurements, and configured, during a survey period, to: record motion data while the measuring device is positioned at a plurality of locations; and a processing device, configured to: determine, using dead reckoning and based on the motion data, a set of survey measurements, each survey measurement comprising a position and orientation of the measuring device at one of the plurality of locations; wherein the or a further measuring device is further configured, during a further survey period, to: record alignment motion data while the or the further measuring device is positioned at one or more survey features determined based on the set of survey measurements; and record further motion data while the or the further measuring device is positioned at a further plurality of locations; and wherein the processing device is further configured to: determine an alignment position and an alignment direction based on the alignment motion data; and determine, using dead reckoning and based on the further motion data, a set of further survey measurements, each further survey measurement comprising a position and orientation of the or the further measuring device at one of the further plurality of locations; and align the set of survey measurements with the set of further survey measurements based on the alignment position and the alignment direction.According to the invention in an aspect, 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 any method described herein.

[0030] Brief description of the drawings

[0031] Embodiments of the disclosed methods and apparatus will be described in detail below, with reference to the accompanying drawings, in which:

[0032] Figure 1 is a schematic representation of a system for determining topographic data;

[0033] Figure 2 is a schematic representation of a measuring device;

[0034] Figure 3 is a schematic representation of a processing device;

[0035] Figure 4 is a plan view of a room of a building;

[0036] Figure 5 is a flow diagram of a method for determining a position of a survey measurement in a local coordinate system; and

[0037] Figures 6a-6d show exemplary positions of the measuring device for determining an alignment position and an alignment direction.

[0038] Detailed Description

[0039] Generally, disclosed in this specification are methods and apparatus for aligning two or more sets of survey measurements. This may allow separate sets of measurements, recorded independently and possibly relating to separate sets of features of a survey to be aligned with each other. Separate sets of survey measurements may be recorded during a survey so they can be identified in separate layers and handled independently in CAD software. Separate rooms may have a different layer, for example, as may windows, doors, walls and other building features. Similar principles are often applied to surveys of the external environment. Separate sets of measurements may also be recorded because of interruptions to the working schedule of a user, such as breaks and the end of the working day. In exemplary arrangements, the separate sets of survey measurements may be recorded in separate survey sessions that are temporally separate, such that an accuracy of an inertial sensor has drifted to unacceptable levels. The methods and apparatus disclosed allow an inertial sensor to be used at a later time and to remove or mitigate inaccuracies due to drift errors.

[0040] As used herein, the term ‘survey measurement’ encompasses a measurement of one or both of position and orientation of a feature to be surveyed. The position measured in a surveymeasurement may be in one or more of x, y and z coordinates based on a frame of reference. The orientation measured in a survey measurement may be in one or more of pitch (rotation about the y-axis), roll (rotation about the x-axis) and yaw (rotation about the z-axis). That is, the position and / or orientation may be in one, two or three dimensions. In exemplary arrangements, a survey measurement may be a position and / or orientation of a measuring device when placed against a survey feature, such as a wall.

[0041] As used herein, the term ‘set of measurements’ encompasses an initial measurement, a plurality of further measurements that are each relative to the previous measurement, and a final measurement. This may be done, for example, using a dead reckoning method, such as with motion data recorded by inertial sensors forming part of an Inertial measurement unit (IMU). The next measurement recorded after a set of measurements will be ‘standalone’ in that it is not relative to any measurement of the previous set of measurements. In exemplary arrangements, the next measurement recorded after a set of measurements may be a further initial measurement of a further set of measurements. Typically, there is no motion data recorded that can be used to determine the position and / or orientation of the next measurement with respect to the previous set of measurements. In some examples, the final measurement of the set may be taken at a known and / or previously measured location so as to mitigate errors.

[0042] Accordingly, a set of survey measurements may include an initial, standalone, measurement, a plurality of measurements dependent from and based on the initial measurement (e.g. by dead reckoning) and optionally a closing measurement aimed at reducing drift error in the set of measurements.

[0043] It is noted that the term ‘orientation’ is used throughout this document and may encompass three dimensional orientation (to define a plane) and two dimensional orientation (to define a line). Exemplary embodiments are described herein that produce plans of surveys. Orientation may be horizontal orientation. In some arrangements, only rotation about the local vertical (local z-axis) is used when determining the orientation of the measuring device. Similarly, the term ‘position’ as used herein can be three-dimensional or two-dimensional position. In some exemplary arrangements discussed position may be only the horizontal component of position.

[0044] Exemplary methods and apparatus may align survey features derived from a first set of survey measurements with those derived from a second set of survey measurements. For example, methods and apparatus described in this document may allow:• Aligning separate rooms of a building with each other;

[0045] • Capturing position and orientation of objects within a room or space and aligning them with the room or space;

[0046] • Aligning buildings relative to other buildings;

[0047] • Capturing the relative position and orientation of areas, e.g. features within a garden perimeter such as patios, pools, beds and external buildings and aligning them with a further area or building.

[0048] The first and second set of measurements may be temporally separated. The temporal separation may be such that the accuracy of the inertial sensors has become too low to align the second set of measurements with the first set of measurements. Alternatively, or in addition, the first set of measurements and the second set of measurements may be positionally separated, in that there is no motion or position data recorded that links the two sets of measurements in a local coordinate frame.

[0049] As used herein, the term ‘survey measurement’ encompasses a position and / or orientation of a measuring device at a survey location. The term ‘survey feature’ is a feature of the environment, the position and / or orientation of which may be determined based on one or more survey measurements. Survey measurements may be coincident with survey features, although they need not be. In an example, a survey measurement may be a position and orientation of the measuring device when placed against a wall of a building. A corresponding survey feature may be a wall defined by a plane derived from the position and orientation. A further survey feature may be a corner where the wall meets a second wall.

[0050] Exemplary methods and apparatus described in this document use a measurement device including motion sensors to record motion data comprising linear and / or rotational motion of the measuring device. Based on the motion data, a first set of survey measurements is determined during a first survey period. During a second survey period, the measuring device can be placed at the location of a survey measurement(s) obtained during the first survey period (or a survey feature derived from the survey measurements). This allows the subsequent survey measurements to be positionally and rotationally aligned with the first set of survey measurements.

[0051] During the second survey period, two axes of a coordinate system may be determined that are aligned with the first set of survey measurements. The axes may be orthogonal and maybe locally level. The term ‘locally level’ as used herein encompasses a horizontally aligned 2-dimensional representation of a survey.

[0052] After the axes are determined, the measuring device may be moved to a further location to record motion data and determine one or more survey measurements of a second set. The second set of survey measurements are determined relative to the axes of the coordinate system and are thereby aligned with the first set of survey measurements.

[0053] Figure 1 shows a schematic representation of an exemplary system 100. 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 motion data representing its position and / or orientation. For example, the one or more sensors may be configured to record motion data comprising linear accelerations and rotational velocities.

[0054] The measuring device 102 is configured to transmit to the processing device 104 measured data representing its position and / or orientation.

[0055] The processing device 104 includes a processor for determining survey data (e.g. survey measurements and / or survey features) based on the motion data. The processing device 104 may be configured to present an indication of the survey data to a construction worker. In some exemplary arrangements, the processing device 104 may be configured to export data representing at least part of the determined survey data. The exported data may, for example, be suitable for representation in CAD software, or the like.

[0056] It will be appreciated that at least part of the processing of the measured motion 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.

[0057] 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.

[0058] The transmission of motion 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 aradio 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.

[0059] The transmission of measured motion 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 102 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 motion 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.

[0060] 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.

[0061] 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 all or part of the 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). The processor 208 is configured to undertake one or more of the functions necessary for operation of one or more of the remaining elements of the measuring device 102.

[0062] The inertial sensors 214 may comprise accelerometers and / or rate gyros. The inertial sensors 214 may be arranged to measure acceleration and rotational velocity of the measuring device102 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 coordinate system or reference frame based on a 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.

[0063] Throughout this document, inertial sensors are referred to, although it should be understood that other motion or positioning sensors may be employed. 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, lasers etc. In embodiments, the measuring device 102 may use only motion and positioning sensors for dead reckoning techniques and in a specific embodiment may use only inertial sensors.

[0064] Each of the transmitter 202 and receiver 204, memory 206, processor 208 and inertial sensors 214 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.

[0065] 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.

[0066] 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 determiner 314, an axis determiner 316 and a plangenerator 320. The processing device 104 also optionally comprises a display 322 and a user interface 324.

[0067] Each of the transmitter 302 and receiver 304, memory 306, processor 308, display 322 and user interface 324 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 determiner 314, axis locator 316 and plan generator 320 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 determiner 314, axis locator 316 and plan generator 320, but are not limited to such.

[0068] Figure 4 shows a plan 400 of a ground floor of an exemplary building. The plan 400 includes a living / kitchen area 402, a bathroom 404 and an office / study 406. In the kitchen / living area, there is a fixed island 408. When surveying the interior of the building, a surveyor may want to measure the dimensions of each room 402, 404 and 406. The surveyor may also want to measure the dimensions and location of the fixed island 408. In addition to the dimensions of these features of the building, the surveyor may also want to place them in separate layers that may be independently manipulated in a suitable software package. To achieve this, each room 402, 404, 406 and the fixed island may be surveyed by obtaining separate sets of survey measurements. In addition, the surveyor will also only have time to measure the dimensions of the kitchen / living area 402 before taking a lunch break and measuring the remainder of the ground floor after lunch, which might also require separate sets of survey measurements before and after lunch. Relative alignment of the sets of survey measurements may be determined using methods and apparatus disclosed herein.

[0069] For the purposes of this description, the term “survey feature” may encompass any part of the built or natural environments to be surveyed. The dimensions of one feature may be determined independently of the dimensions of another feature. The alignment of the various features may not be understood from the survey measurements relating to the features alone.

[0070] Figure 5 shows a flow diagram of an exemplary method of aligning sets of survey measurements.At step 500, during a first surveying period, the measuring device 102 is placed at a first location, in this case against a first wall 410 of the kitchen / living area 402. However, it will be appreciated that the measuring device 102 may be placed at any of a plurality of locations, which may be locations of features to be surveyed in a first set of survey measurements. In the example described here, the features to be surveyed are the internal walls of the kitchen / living area 402 and exemplary apparatus are configured to determine the location and alignment of the walls, as described below.

[0071] Motion data is recorded by the measuring device 102 at step 502. In exemplary arrangements, the motion data is recorded throughout the first survey period, during which the measuring device 102 is positioned at the plurality of locations. The motion data recorded by the measuring device may be transmitted to the processing device 104 for processing. This may be done in real time or at a later time. Accordingly, the steps of the flow diagram of Figure 5 may be conducted out of the order described herein. An initial position and orientation of the measuring device 102 during the first survey period may be determined based on the motion data at the time the measuring device is placed in the first location.

[0072] At step 504, the measuring device 102 is positioned at the remaining locations of the plurality of locations. In the exemplary arrangement disclosed here, the measuring device 102 is positioned against the remaining indoor walls of the kitchen / living area 402, for example walls 412, 414, 416, 418 and so on around all internal walls.

[0073] Motion data is recorded whilst the measuring device is moved to and placed at the plurality of locations. The motion data can be processed to resolve a position and orientation of the measuring device 102 at each of the plurality of locations, which in this case are the locations of the measuring device 102 when placed on each of the internal walls of the kitchen / living area 402.

[0074] In exemplary arrangements, the measuring device 102 may also be used to determine the location of openings in the walls 410, 412, 414, 416, 418, such as windows and doorways. Figure 4a shows an exemplary method for this. Internal wall 416 is split by a doorway 420 into two sections 416a, 416b. The measuring device 102 may be placed at a first of the plurality of locations on the section of wall 416a. The measuring device 102 may then be placed on the inside surface of each doorjamb 420a, 420b. The measuring device 102 may then be placed at a location on the wall section 416b. Obtaining motion data at each of these locations allows the position and width of the doorway 420 to be determined.A first set of survey measurements are determined at step 506 by the position and orientation determiner 314. The first set of survey measurements are the positions and orientations of the measuring device 102 at each of the plurality of locations, which in this case are locations on each of the internal walls of the kitchen / living area 402, and also on the inside surfaces of any openings such as the doorway 420. The positions and orientations are determined by dead reckoning based on the initial position and orientation of the measuring device 102, and the motion data recorded during the first survey period. This will be readily understood by the skilled person.

[0075] The first set of survey measurements are closed at step 508. Closing a set of survey measurements comprises ending the dead reckoning process. This may include ending the recordal of motion data that has a reference to the initial position and orientation of the measuring device 102. Accordingly, the position and orientation of the next recorded survey measurement after the first set of survey measurements cannot be determined with respect to the first set of survey measurements. In some exemplary arrangements, closing the first set of survey measurements may comprise placing the measuring device at the location of a previous survey measurement of the first set of survey measurements. This can allow errors to be mitigated.

[0076] Based on the first set of survey measurements, a first set of survey features may be determined at step 510. The survey features may comprise the survey measurements themselves (i.e. they may be coincident with the locations at which the survey measurements were recorded). For example, a survey feature may be the fixed island 408 and the survey measurements may be position and optionally orientation of the measuring device 102 at each of the four corners of the fixed island 408.

[0077] The first set of survey features may comprise features of a surveyed area that are extrapolated from the first set of survey measurements. For example, in the example described here, an internal wall 410, 412, 414, 416, 418 may be positioned in the survey area based on the position and orientation of the measuring device 102 when the measuring device 102 was placed on that wall. A line representing the wall can be drawn at the position of the measuring device 102 and aligned with a horizontal component of the orientation of the measuring device 102. When multiple walls are drawn in the same way then intersections between the walls (i.e. corners of the room) can be determined. Accordingly, based on a survey measurement, the survey feature of a wall may be determined that includes the locations of the corners of the room even though these were never directly surveyed.After closing the first set of survey measurements, a second set of survey measurements may be determined during a second survey period. At the beginning of the second survey period, no motion data is available that can determine the position and / or orientation of the measuring device 102 relative to any of the first set of survey measurements.

[0078] At step 512, the measuring device 102 is placed at one or more of the first survey features determined based on the first set of survey measurements. As mentioned above, the survey features may be coincident with the position and / or orientation of one or more of the plurality of first survey measurements, or may be coincident with locations that have been determined based on one or more of the first set of survey measurements (such as corners of a room).

[0079] Motion data is recorded 514 and this is processed by the axis locator 316 of the processing device 104 to determine an alignment position and an alignment direction. The alignment position comprises a position that may be represented relative to the first set of survey measurements. The alignment direction comprises a direction that may be represented relative to the first set of survey measurements. The axis locator 316 may determine a coordinate system comprising first and second axes and an origin using the alignment position and the alignment direction. The second set of survey measurements may be determined in the coordinate system, thereby aligning the second set of survey measurements with the first set of survey measurements.

[0080] Figs. 6a-6d show the locations of exemplary survey features at which the measuring device 102 may be placed to determine an alignment position and alignment direction, such that the second set of survey features may be aligned with the first set of survey features.

[0081] Fig. 6a shows a representation of the wall sections 416a, 416b and the doorway 420 shown in Figs. 4 and 4a. The doorway 420 leads from the kitchen / living area 402 to the bathroom 404 It will be understood that the wall sections 416a, 416b are only exemplary and any wall sections with any type of opening therein (e.g. a window) may be used. Moreover, the same principle may be applied to any survey feature that has a known alignment and a known position based on the first set of survey features, such as an internal or external corner of a room. In this case, only horizontal orientation and position is needed.

[0082] In Fig. 6a, the measuring device 102 may be placed at the point 600, which is a survey feature determined based on the first set of survey measurements. It is noted that the measuring device 102 may be placed at any point that is derived from the first set of survey measurements and has a known position and orientation, at least in 2 dimensions, e.g. plan.The survey feature in this example is an edge of the wall section 416a, where it meets the doorway 420. The horizontal position of the edge of the wall section 416a and the horizontal orientation of the wall section 416a are known from the first set of survey features.

[0083] The edge of the wall section 416a is determined based on the first set of survey measurements and its position is known relative to the first set of measurements. Therefore, the position and orientation determiner 314 may process the motion data recorded during the second survey period to determine the position of the measuring device 102. The axis locator 316 sets the determined position to be the alignment position.

[0084] In addition, the horizontal orientation of the wall section 416a is known relative to the first set of survey measurements. Therefore, the position and orientation determiner 314 may process the motion data to determine the orientation of the measuring device 102. The axis locator 316 sets the determined horizontal orientation to be the alignment direction.

[0085] In exemplary arrangements, the axis locator 316 may create a first axis 604 that is aligned with the alignment direction. The axis locator 316 may further determine a second axis 606 to be orthogonal to the first axis 604. An origin 608 of the first and second axes 604, 606 is determined to be the alignment position.

[0086] In the example of Fig. 6b, the measuring device 102 is placed at two survey features 600, 602. in the exemplary arrangement shown, the first survey feature 600 is the same as the survey feature 600 in Fig. 6a. The second survey feature 602 is an edge of the wall section 416b, where it meets the doorway 420. This survey feature is determined based on the first set of survey measurements so its position is known relative to the first set of measurements. It will be understood that only one of the survey features 600, 602 needs to be at a position known based on the first set of survey measurements. This position allows placement of the origin (in this case 602). The alignment direction is obtained based on the relative alignment of the two survey features 600, 602.

[0087] The position and orientation determiner 314 may process the motion data recorded during the second survey period to determine the position of the measuring device 102 at each of the survey features 600, 602. The axis locator 316 sets the alignment position to be one of the determined positions of the measuring device 102 at the survey features 600, 602.

[0088] The axis locator 316 may further mitigate error in the determination of the alignment position based on the positions of the measuring device 102 at the survey features 600, 602. The axislocator 316 may determine the distance and direction from the position at the first survey feature 600 to the position at the second survey feature 602. This may be compared to the corresponding distance and alignment in the first set of survey features. Any difference may be used to reduce error in the alignment position.

[0089] The axis locator 316 may determine the alignment direction to be a direction between the position at the first survey feature 600 and the position at the second survey feature 602. The axis locator 316 may further mitigate any error in the alignment direction based on the orientation of the measuring device 102 at the first and / or second survey features 600, 602. The axis locator 316 may compare the determined orientations of the survey features with the corresponding orientations in the first set of survey features. Any difference may be used to reduce error in the alignment direction.

[0090] In Fig. 6c, the measuring device 102 is placed at a point 610 on the wall section 416a. The measuring device 102 is also placed at a point 612 on the inner surface of the doorjamb 420a. It is noted that the measuring device 102 need not be placed at any precise location on the wall section 416a and the door jamb 420a, and not at the precise location of the corresponding first survey measurement in the first set of survey measurements. The measuring device 102 may be placed at any point on the relevant survey feature. In the example of Fig. 6c, points 610 and 612 may be anywhere on the wall section 416a and doorjamb 420a respectively.

[0091] The position and orientation determiner 314 determines the position and orientation of the measuring device 102 at the points 610, 612 based on the motion data recorded during the second survey period. The axis locator 316 determines the alignment direction to be aligned with one of the wall section 416a and the inner surface of the doorjamb 420a. The axis locator 316 determines an alignment position to be an intersection between the wall section 416 and the inner surface of the door jamb 420a. The intersection may be determined based on a projection of the orientations of the measuring device 102 at each of the points 610, 612.

[0092] In exemplary arrangements, the axis locator 316 may create first and second axes 604, 606, wherein at least one axis is aligned with the alignment direction, the other axis being orthogonal to it. The alignment position is determined to be the origin 608 of the first and second axes 604, 606.

[0093] In Fig. 6d, the measuring device is placed at four survey features 600, 602, 614, 616, although more may be used. Survey features 600 and 602 are the same as those described above in respect of Fig. 6b, although as discussed above other survey features having a known positionand orientation may be used. The measuring device 102 may be placed at additional survey features 614, 616, which in the example of Fig. 6d are the wall sections 416a, 416b. As mentioned above, the precise location of the measuring device 102 on the wall section 416a and 416b need not be important.

[0094] The position and orientation determiner 314 determines the position and orientation of the measuring device 102 at the points 600, 602, 614, 616 based on the motion data recorded during the second survey period. As in the example of Fig. 6b, the axis locator 316 sets the alignment position to be one of the determined positions of the measuring device 102 at the survey features 600, 602. Similarly, the axis locator 316 may determine the alignment direction to be a direction between the position at the first survey feature 600 and the position at the second survey feature 602. It will be appreciated that the alignment direction may be set to a direction between the determined position of the measuring device at any of the points 600, 602, 614, 616.

[0095] As in the example of Fig. 6b, the axis locator 316 may further mitigate error in the determination of the alignment position based on the determined positions of the measuring device 102 at the survey features 600, 602. The axis locator 316 may further mitigate any error in the alignment direction based on the orientation of the measuring device 102 at any of survey features 600, 602, 614, 616. Optionally, the axis locator 316 may further mitigate any error in the alignment direction based on a direction between the determined positions of the measuring device 102 at the survey features 600, 602, 614, 616, and in particular the direction between points 600 and 614, and 602 and 616.

[0096] By determining the axes 604, 606 and the origin 608, the axis locator 316 is able to align the first set of measurements to the second set of measurements to be recorded. This can be done in real time or in post-processing. It is noted that the placements of the first and second axes 604, 606 and the origin 608 are arbitrary. The specific location and alignment is not relevant, only that they are known with respect to the first set of survey measurements.

[0097] At step 516, the measuring device is placed at a second plurality of locations that are to be surveyed, which in this example are the walls of the bathroom 404. A second set of survey measurements are determined at step 518, based on the motion data that has been recorded and using dead reckoning. Based on the second set of survey measurements, a second set of survey features may be determined.The second set of survey measurements, and therefore the second set of survey features are aligned with the first set of survey measurements based on the alignment position and direction discussed above.

[0098] The plan generator 320 may generate a plan based on the first and second survey features.

[0099] In exemplary arrangements, an algorithm operating on the processor 408 of the processing device may detect that measurements of one feature have been completed and / or that measurements of a further feature have begun. Such algorithms are not explained in detail herein. Alternatively, the construction professional may indicate through the user interface 322 that measurements of one feature have been completed and / or that measurements of a further feature have begun.

[0100] In exemplary arrangements, the measuring device 102 may include a reference point. The reference point may be a location or surface on the measuring device 102 at which the position and / or orientation of the measuring device 102 is to be calculated.

[0101] 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.

[0102] 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).

[0103] 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.

[0104] 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).

[0105] 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.

[0106] 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.

[0107] 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. A method of aligning first and second sets of survey measurements, wherein the first and second sets of survey measurements are recorded using a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device, the method comprising:during a first survey period:positioning the measuring device at a first plurality of locations;recording first motion data at the measuring device; anddetermining, using dead reckoning and based on the first motion data, a first set of survey measurements, each of the survey measurements in the first set comprising a position and orientation of the measuring device at one of the plurality of first locations;during a second survey period:positioning the or a further measuring device at one or more survey features determined based on the first set of survey measurements;recording alignment motion data while the or the further measuring device is at the one or more survey features;determining an alignment position and an alignment direction based on the alignment motion data;positioning the or the further measuring device at a second plurality of locations;recording second motion data of the or the further measuring device; and determining, using dead reckoning and based on the second motion data, a second set of survey measurements, each of the survey measurements in the second set comprising a position and orientation of the measuring device at one of the second plurality of locations; andaligning the first set of survey measurements with the second set of survey measurements based on the alignment position and the alignment direction.

2. The method according to claim 1, wherein the one or more of the survey features comprises a survey feature having a known position and orientation,and wherein determining the alignment position comprises determining a position of the measuring device at the survey feature, and determining the alignment direction comprises determining an orientation of the measuring device at the survey feature.

243. The method according to claim 1, wherein the one or more of the survey features comprise a first survey feature having a known position, and a second survey feature having a known position,wherein determining the alignment position comprises determining a position of the measuring device at the first survey feature,and wherein determining the alignment direction comprises determining a position of the measuring device at the second survey feature, and determining a direction between the position of the measuring device at the first survey feature and the position of the measuring device at the second survey feature.

4. The method according to claim 3, wherein determining the alignment position further comprises mitigating an error in the determination of the position of the measuring device at the first survey feature based on the position of the measuring device at the second survey feature.

5. The method according to claim 3 or 4, wherein the first survey feature and / or the second survey feature has a known orientation, and wherein determining the alignment direction comprises mitigating an error in the determination of the direction between the position of the measuring device at the first survey feature and the position of the measuring device at the second survey feature based on an orientation of the measuring device at the first and / or second survey feature.

6. The method according to any of claims 3 to 5, wherein the one or more survey features comprises at least one additional survey feature having a known position and / or orientation, and wherein determining the alignment position and / or alignment direction comprises determining a position and / or orientation of the measuring device at the at least one additional survey feature.

7. The method according to claim 1, wherein the one or more of the survey features comprises a first survey feature having a known orientation, and a second survey feature having a known orientation, and wherein the orientations of the first and second survey features are transverse to each other,wherein determining the alignment position comprises determining an intersection of the orientations of the measuring device at the first and second survey features,and wherein the alignment direction is determined to be the orientation of the measuring device at the first or second survey features.

8. The method according to claim 7, wherein the first and second survey features form a corner defined by surfaces of room or building.

9. The method according to claim 7 or 8, wherein the first survey feature comprises a wall of a room or building, and wherein the second survey feature comprises an internal surface of an opening in the wall of the room or building.

10. The method according to any preceding claim, further comprising defining a coordinate system based on the alignment position and alignment direction,the alignment direction defining a first axis, the alignment position defining an origin, and a second axis being defined transverse to the first axis.

11. The method according to claim 10, further comprising determining the second set of survey measurements in the coordinate system12. The method according to any preceding claim, wherein at least one of the one or more survey features is an end of a wall.

13. The method according to any preceding claim, wherein the motion data comprises only inertial sensor data.

14. A method of aligning first and second sets of survey measurements, the method comprising:receiving first motion data recorded during a first survey period using a measurement device comprising a plurality of sensors configured to obtain motion data, including linear and rotational motion of the measuring device;determining, using dead reckoning and based on the first motion data, a first set of survey measurements, each of the survey measurements in the first set comprising a position and orientation of the measuring device at one of a first plurality of locations;receiving alignment motion data recorded during a second survey period using the or a further measurement device, wherein the alignment motion data has been recorded while the or the further measuring device was positioned at one or more survey features determined based on the first set of survey measurements;determining an alignment position and an alignment direction based on the alignment motion data;receiving second motion data recorded while the or the further measuring device was positioned at a second plurality of locations;determining, using dead reckoning and based on the second motion data, a second set of survey measurements, each of the survey measurements in the second set comprising a position and orientation of the measuring device at one of the second plurality of locations; andaligning the first set of survey measurements with the set of second set of survey measurements based on the alignment position and the alignment direction.

15. A computer program product comprising computer code configured, when executed by a computer processor, to carry out the method of claim 14.

16. An apparatus for aligning first and second sets of survey measurements, the apparatus comprising one or more computer processors configured to:receive first motion data recorded during a first survey period using a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device;determine, using dead reckoning and based on the first motion data, a first set of survey measurements, each survey measurement in the first set comprising a position and orientation of the measuring device at one of a plurality of first locations;receive alignment motion data recorded during a second survey period using the or a further measurement device, wherein the alignment motion data has been recorded while the or the further measuring device was positioned at one or more survey features determined based on the first set of survey measurements;determining an alignment position and an alignment direction based on the alignment motion data;receive second motion data recorded while the or the further measuring device was positioned at a second plurality of locations;determine, using dead reckoning and based on the second motion data, a set of second survey measurements, each survey measurement in the second set comprising a position and orientation of the measuring device at one of the second plurality of locations; andalign the first set of survey measurements with the second set of survey measurements based on the alignment position and the alignment direction.

17. A system for aligning sets of survey measurements, the system comprising:a measurement device comprising a plurality of sensors configured to obtain motion data including linear and rotational motion of the measuring device, and configured to record survey measurements, and configured, during a survey period, to:record first motion data while the measuring device is positioned at a plurality of first locations; anda processing device, configured to:determine, using dead reckoning and based on the first motion data, a first set of survey measurements, each survey measurement in the first set comprising a position and orientation of the measuring device at one of the first plurality of locations; wherein the or a further measuring device is further configured, during a second survey period, to:record alignment motion data while the or the further measuring device is positioned at one or more survey features determined based on the first set of survey measurements; andrecord second motion data while the or the further measuring device is positioned at a second plurality of locations;and wherein the processing device is further configured to:determine an alignment position and an alignment direction based on the alignment motion data; anddetermine, using dead reckoning and based on the second motion data, a second set of survey measurements, each survey measurement in the second set comprising a position and orientation of the or the further measuring device at one of the second plurality of locations; andalign the first set of survey measurements with the second set of survey measurements based on the alignment position and the alignment direction.

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