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Accurate localization and mapping are essential for mobile robots. Using laser rangefinders (LRFs), current state-of-the-art indoor Simultaneous Localization and Mapping (SLAM) can provide accurate...

In this paper, we report the results of investigations on the drone ballistic carriers being developed by our research team and we address specifically the concept of compact laser altimeter dedicated to the ballistic carriers. One of the main challenges facing the implementation of the mortar launched altimeter is to ensure its reliable operation after extremely high launch shock accelerations. This requirement determines the optical concept and materials selection and optimization. Recent mortar gun tests demonstrated that the optical and electronic sub-systems of the first altimeter prototype can withstand launch accelerations of at least 5000g.

We present a novel method for extrinsically calibrating a camera and a 2D Laser Rangefinder (LRF) whose beams are invisible from the camera image. We show that point-to-plane constraints from a single observation of a V-shaped calibration pattern composed of two non-coplanar triangles suffice to uniquely constrain the relative pose between two sensors. Next, we present an approach to obtain analytical solutions using point-to-plane constraints from single or multiple observations. Along the way, we also show that previous solutions, in contrast to our method, have inherent ambiguities and therefore must rely on a good initial estimate. Real and synthetic experiments validate our method and show that it achieves better accuracy than previous methods., Comment: 12 pages, 12 figures

One of the key issues that prevents creation of a truly autonomous mobile robot is the simultaneous localization and mapping (SLAM) problem. A solution is supposed to estimate a robot pose and to build a map of an unknown environment simultaneously. Despite existence of different algorithms that try to solve the problem, the universal one has not been proposed yet [1]. A laser rangefinder is a widespread sensor for mobile platforms and it was decided to evaluate actual 2D laser scan based SLAM algorithms on real world indoor environments. The following algorithms were considered: Google Cartographer [2], GMapping [3], tinySLAM [4]. According to their evaluation, Cartographer and GMapping are more accurate than tinySLAM and Cartographer is the most robust of the algorithms.

The object of research is a laser rangefinder with a wireless sensor network interface protocol ZigBee, which in this study is proposed for the function of measuring the distance between objects. The main spheres of application are spheres where reliable information about the location of objects relative to each other is required. To increase the reliability, it is proposed to combine the possibility of measuring the distance between objects of sensor networks and data obtained from a laser rangefinder. These two methods are combined in one device. One of the most problematic places is the error of the measuring equipment. Also, for the objects described above, various obstacles are typical, like mechanical (trees, hills, lowlands), and radio interference. In the course of the research, the method of increasing the accuracy of measuring the distance of wireless sensor networks was used. To do this, they are combined with laser rangefinders, which are part of computerized distance measuring systems built on the basis of a combination of measurement methods of a different nature. Site localization studies were carried out for the average deviation value when ranking in 1 m (20 measurements), as well as on the progressive function of the required number of transactions. To calibrate the measured measurements, a minimum period of two-sided pass was calculated for the average value, when the receivers are in close proximity to one another (0.01 m). This average value on was calculated from each ranking measurements before converting to an immediate distance value. The results confirm an improvement in the efficiency of the ranking by averaging a plurality of samples to an error value of 6.0 m. The accuracy of the method was constant throughout the test propagation range (within a radius of 250 m).

Passively Q-switched Er:Yb:LuAl3(BO3)4 pulse microlasers were investigated at a low repetition frequency of 10–200 Hz. End-pumped by a 975.6 nm quasi-continuous-wave laser diode with pump pulse width of 0.5 ms and period of 10 ms, a stable 1522 nm pulse microlaser with single pulse energy of 48.3 μJ, duration of 1.9 ns, repetition frequency of 100 Hz, peak output power of 25.4 kW and beam quality factor less than 1.2 was realized at a pump beam waist diameter of 260 μm. This eye-safe passively Q-switched pulse microlaser with high peak output power and narrow duration can be used in the portable laser rangefinder.

An integrated receiver-TDC (time-to-digital converter) chip set is developed for pulsed time-of-flight (TOF) laser rangefinding. The receiver detects the current pulse from the optical detector and produces a timing mark for the TDC. The receiver uses time mode walk error compensation scheme achieving

We propose and characterize a novel and simple architecture of dual-frequency noise rangefinder aiming at achieving high precision and robustness with reduced hardware requirements. In the scheme, the range measurement is achieved by exploiting the differential beat-noise between two lasers. In more detail, the outputs of the two lasers are coupled together and sent to the target. The backscattered echo from the target is acquired by the echo-receiver. The two lasers’ outputs are also sent to the reference-receiver. The range measurement is achieved through the digital cross-correlation between the lasers’ beat-noise information acquired by the two receivers. A laboratory demonstration shows range accuracy and resolution of 3.6 mm and 0.8 m, respectively, well in accordance with the signal/noise-dependent theoretical boundary values.

We present a new method for calibrating a single-point laser rangefinder and single camera because the combination of a cheap single-point laser range finder (LRF) and a camera has become increasingly helpful in recent industrial applications. In order to effectively use the date from the camera and LRF, it is important to know their relative position and orientation from each other. In this paper, a robust extrinsic calibration method for determining the position and direction of the LRF with respect to the camera is proposed. Due to the spot of the single-point LRF we commonly use is mostly invisible, infrared camera is utilized to detect laser spot and then establish the position relationship between visible light camera and infrared camera to calibrate the extrinsic parameters. Experimental results demonstrate that the proposed method can calibrate the extrinsic parameters with high precision and effectively.

A laser rangefinder device based on pulsed time-of-flight (TOF) distance measurement techniques was constructed and tested. Key blocks of the system are the integrated receiver channel and the integrated time-to-digital converter (TDC) fabricated in a 0.35-um CMOS technology. The receiver-TDC chip set is capable of measuring the time position, rise time and pulse width of incoming optical pulses with ps precision in the amplitude range of more than 1: 50 000. The timing detection is based on leading edge detection in the receiver channel, and the amplitude-dependent timing error is compensated for by utilizing the multichannel TDC. A measurement distance of 100 m is achieved to a target with a reflectance of about 10% at the signal level of SNR = 6, with an optical output power and receiver aperture of 12 W and 18 mm, respectively.

A laser rangefinder system for monitoring Ust-Kamenogorsk shipping lock’s wall deviations caused by seasonal thermal deformations and dynamic loads related to the lock filling/emptying is described, as well as the results of 8.5-year observations. The Ust-Kamenogorsk shipping lock has a high-head single-lift chamber 47 m in depth. A trend toward a decrease in the chamber width with a rate of ~2.2 mm/year in the upper part of the lock is ascertained. The effect of the chamber filling/emptying on the dynamics of wall deviations is studied.

For the non-stationary environment simulation in laser range finder product testing, a new dynamic target simulation system is studied. First of all, the three-pulsed laser ranging principle, laser target signal composition and mathematical representation are introduced. Then, the actual nonstationary working environment of laser range finder is analyzed, and points out that the real sunshine background light clutter and target shielding effect in laser echo become the main influencing factors. After that, the dynamic laser target signal simulation method is given. Eventlly, the implementation of automatic test system based on arbitrary waveform generator is described. Practical application shows that the new echo signal automatic test system can simulate the real laser ranging environment of laser range finder, and is suitable for performance test of products.

We present a novel method for extrinsically calibrating a camera and a 2-D Laser Rangefinder (LRF) whose beams are invisible from the camera image. We show that point-to-plane constraints from a single observation of a V-shaped calibration pattern composed of two non-coplanar triangles suffice to uniquely constrain the relative pose between two sensors. Next, we present an approach to obtain solutions using point-to-plane constraints from single or multiple observations. Along the way, we also show that previous solutions, in contrast to our method, have inherent ambiguities and therefore must rely on a good initial estimate. Real and synthetic experiments validate our method and show that it achieves better accuracy than previous methods.

Many applications, like mobile robotics, can profit from acquiring dense, wide-ranging and accurate 3D laser data. Off-the-shelf 2D scanners are commonly customized with an extra rotation as a low-cost, lightweight and low-power-demanding solution. Moreover, aligning the extra rotation axis with the optical center allows the 3D device to maintain the same minimum range as the 2D scanner and avoids offsets in computing Cartesian coordinates. The paper proposes a practical procedure to estimate construction misalignments based on a single scan taken from an arbitrary position in an unprepared environment that contains planar surfaces of unknown dimensions. Inherited measurement limitations from low-cost 2D devices prevent the estimation of very small translation misalignments, so the calibration problem reduces to obtaining boresight parameters. The distinctive approach with respect to previous plane-based intrinsic calibration techniques is the iterative maximization of both the flatness and the area of visible planes. Calibration results are presented for a case study. The method is currently being applied as the final stage in the production of a commercial 3D rangefinder.

Laser may cause disfunction or even damage to laser rangefinder. Based on evaluation rules of high repetition rate laser jam pulsed laser rangefinder, the principles of distance deception and blinding jamming were analysed and the jamming success rate was calculated. We also set up a calculation example for 100 kHz repetition rate laser jam certain type rangefinder. The result showed that we can obtain jamming grade and success rate, accomplish the quantitative evaluation of the laser jamming effect.

In this paper, an external parameter calibration method for multiple cameras with non-overlapping fields of view (FOVs) using a laser rangefinder (LRF) is presented. The proposed method combines multiple cameras by the laser beam projected by the LRF. The main procedures of the proposed method are: The LRF is positioned for a few (at least two) times and projects a laser beam across the FOVs of different cameras. The laser beam is intercepted by a planar object for at least 3 times in the FOV of each camera. The cameras capture the laser spots projected on the planar object and the LRF measures the distances between the different spots. According to the co-linearity of the laser spots captured by all the cameras at each LRF position and the distances between the laser spots, the external parameters between different cameras can be computed. If the laser beam cannot reach the FOVs of all the cameras, the calibration of all the cameras can be achieved by pair-wise calibration. Experiment results show that the relative point pair distance error is around 0.3‰ when the distance between the two cameras is around four meters.

To reduce the diode laser bar’s smile effect induced by packaging, a method based on a chip mounter is presented. When the bare bar is picked up by the pick-up tool (PUT) of the chip mounter, the curve direction and volume of the bar can be measured by scanning the P side surface of the bar with a laser rangefinder, and they can be controlled through adjusting the setting up of the PUT. By controlling the curve direction and volume at an appropriate state to compensate the packaging induced strain, the obtaining smile effect is restricted within 0.5μm steadily.

The relatively near future of EW will show significant advances in laser designators and new technologies in the offensive and defensive high-intensity laser pulse domain. Apart from the active research fields in various disciplines attaining laser and radar technology, the military laser systems market was estimated to be worth US $3.03 billion in 2015.

We developed a remote control system for maintenance of in-cell type fuel fabrication equipment. The system display recreated three-dimensional information of the workspace from data obtained by laser rangefinder and conventional cameras. It has allowed us to operate a manipulator arm remotely with several control modes. In order to evaluate the effectiveness and usefulness of developed system, we implemented remote handling experiments using mock up equipment. Performance was compared for remote operation conducted using several different display and operation modes. We confirmed that the system is able to maintain in-cell fuel fabrication equipment in each display and operation mode. Times required to complete the remote operations were collected and compared in each mode. It was observed that integration of 3D information from the laser rangefinder reduced operation time and reinforced visual information during remote operation.

Laser rangefinders and laser scanners are widely used for industrial purposes and for remote sensing. In agriculture information about crop parameters like volume, height, and density can support the optimisation of production processes. In scientific papers the measurement of these parameters by low cost laser rangefinders with one echo has been presented for short ranges. Because the cross section area of the beam increases with the measuring range, it can be expected that laser rangefinders will have a reduced measuring accuracy in small sized crops and when measuring far distances. These problems are caused by target areas smaller than the beam and by the beam striking the edges of crop objects. Lab tests under defined conditions and a real field test were performed to assess the measuring properties under such difficult conditions of a chosen low cost sensor. Based on lab tests it was shown that the accuracy was reduced, but the successful use of the sensor under field conditions demonstrated the potential to meet the demands for agricultural applications. Insights resulting from investigations made in the paper contribute to facilitating the choice or the development of laser rangefinder sensors for vehicle based measurement of crop parameters for optimisation of production processes.

We have developed the system to collect disaster information quickly and effectively and executed three experiments. The system can collect the fire damage and the building damage from a high altitude with a laser range finder.This system has the following features: 1)The system can measure the position of the damage place from a high altitude. 2)Investigator's safety can be secured from a fire and the secondary disaster. 3)Damage information at large areas can be collected at short time. 4)It is possible to use it from motorcycle, car, and helicopter.We applied the system to three experiments, and confirmed its validity and effectiveness.

In order to arrange the radiation of a semiconductor laser into parallel circular beams, an optical system consisting of an objective and an anamorphic system of right-angle prisms is proposed. Analytical relationships that determine the design parameters of the system are provided. The use of the proposed system in a laser rangefinder significantly reduces the dimensions of the instrument and increases the maximum measured distance owing to the summation of the power of the radiation from several lasers.

To replace the hand-held laser rangefinders on board transport spacecraft (SC) a laser rangefinder-speedometer (LRS) is developed and installed in the unpressurized area of SC to determine automatically the range rate. Crew, turning the active spacecraft by the video image that is formed by a docking camera, manually provides guidance of LRS to the passive SC. Using a generalized function of efficiency was estimated LRS characteristics. Comparison with the results of existing analogues shows that the LRS has the highest efficiency. As a result of relationship analysis of measuring speed and reliability accuracy of LRS laser source, Pareto sets are obtained, which enable providing the optimal operation conditions of a device It is found that the reliability function of LRS, which is equal to 0.999, is ensured at 1.0 s averaging time of range measurement and 0.8...0.9 m range measurement error. Increasing the averaging time of range measurement up to 1.5 s allows reliability function equal to 0.999 with the range measurement error of 2.5...2.5 m. Energy calculations are performed for 5 km range measurements on space complex with a complicated configuration such as the International Space Station (ISS) for the maximum and minimum value of the effective reflection area. When the laser pulse energy is 11.5 mJ for measurements of diffusely reflected signal at ranges of 5 km at least a signal/noise ratio is no less than 10. With LRS illuminating the angular reflector, a measurement range is of over 30 km. Because of a large number of the angular reflectors on the ISS body is considered the use of the geometric factor to protect the photo-detector overload when receiving a signal from the nearby angular reflector. It is found that when the length of the base between the receiving and transmitting optical apertures is equal to 39 mm, a photo-detector is protected from the overload at the pulse energies up to 11.5 mJ. The results of efficiency evaluation using the generalized functions for different types of laser sources are presented. Optical parametric oscillator based on a neodymium laser with diode pumping has the highest efficiency. With increasing pulse energy and reducing weight and size characteristics of fiber lasers, they may be used in LRS instead of solid-state lasers.

This paper presents a map building method of an autonomous mobile robot's environment. It is based on an original « focus of attention » cooperation system using a laser rangefinder as the main source of information and a video camera mounted on a pantilt unit to perform close inspection of selected objects in the scene; selection of such objects being performed by analysing data from the laser rangefinder. This cooperation process provides a sufficiently rich description of the robot's environment to call for more complex tasks such as localisation.

The laser rangefinder considered here, for measuring short distances (up to 50 m) between objects, is based on the principle of laser signal emission and reflected signal reception. It converts the computed measured distance and shows it on a built-in display panel.

The flue walls in carbon bake furnaces (CBFs) deform over time under cyclic heating and cooling, leading to difficulties in loading/unloading anodes, and inconsistent anode baking. It is useful to regularly measure the deformations to establish the rate of deterioration and assist in the prediction of flue wall life. Boyne Smelters Limited commissioned a new CBF in 2012. During commissioning, CSIRO utilised its 3D laser scanning technology to map the CBF. A sensor payload consisting of a scanning laser rangefinder sensor connected to a logging and processing PC was suspended from a crane and moved over open pits in a pattern to obtain sufficient coverage of internal pit surfaces, as well as some of the CBF floor and walls. The resulting data is useful for comparing the finished CBF to blueprint plans, and serves as a baseline for future scan comparisons to determine deformations of the flue walls and pit floor.

The paper describes practical application of pulsed microchip laser generating at 1535-nm wavelength to a laser rangefinder. The complete prototype of a laser rangefinder was built and investigated in real environmental conditions. The measured performance of the device is discussed. To build the prototype of a laser rangefinder at a reasonable price and shape a number of basic considerations had to be done. These include the mechanical and optical design of a microchip laser and the opto-mechanical construction of the rangefinder.

First, in this report an overview is given on the use of the Russian laser altimeter in space “LORA” as a lidar for cloud measurements. Secondly, the influence of multiple scattering is verified by analysis of the backscatter signals from clouds having the excellent range resolution of a rangefinder.

A new water level measuring system, using laser rangefinder sensor with phase method as laser water level sensor without cooperative target is presented. The laboratory and field experiments have been done to confirm the application field and measuring accuracy of system. The results show that the measuring accuracy could reach to ±1.5 mm in calm water in case that water turbidity value is greater than 300 NTU. Furthermore, the measuring accuracy can reach to ±3mm for the measuring period taking 5 minute in case of the water surface sloshing. The maximum measuring distance of system could reach to 12m.

WOS; International audience; This paper deals with offline nonlinear state estimation where measurements are available only when some given equality conditions are satisfied. For this type of problems, which are often met in robot localization when sonar or radar are involved, the data are qualified as fleeting because the measurements are available only at some given unknown dates. In this paper, the first approach able to deal with nonlinear estimation with fleeting data is presented. An illustration related to offline robot localization with a laser rangefinder will be given.

A new Laser Detection and Ranging or laser radar (LADAR) prototype system has been designed and implemented to be able to capture the 3D LADAR data from the surfaces of various objects. This system is designed to have a high technical specification (sampling rate and resolution) at a minimum cost. This opens up the possibility for further research in the LADAR field, which is currently limited because of the high cost of traditional LADAR systems. This paper describes the technical aspects of the LADAR design which include hardware components and both the mathematical model and the controlling software that are required for reconstructing the resultant LADAR images from the scanning measurements.

This paper reports the design, modeling and characterization of a 2-DoF twisting electrothermal (ET) actuator for reducing parasitic motion in the application of an SOI-CMOS-MEMS-based Scanning Laser Rangefinder (SLR). A schematic-based model was built using a hierarchical MEMS behavioral model library (NODAS) to develop the concept of independently actuating two parallel metal-polysilicon-oxide CMOS-MEMS vertical electrothermal actuators for scanning control. The small in-plane parasitic motion, which is essential for laser alignment, is less than 2 µm. The optical scanning range of 31° about the y-axis and 20° about the x-axis were obtained at 8.6 mW and 14.7 mW, respectively, with a small device footprint of 191 µm – 156 µm.

This paper presents a feature extraction method in scanning laser rangefinder data. Whereas many popular methods use Cartesian coordinates to detect features, the proposed method use a geometric invariant in natural (polar) coordinates. It leads to a membership condition that only depends on the sensor properties (angular resolution and range measurement error).

The project aimed to improve an automatic system for changing feed horn. We developed a precisely positioning unit for the system in the place of manual feed which might cause seriously decreasing of accuracy because of aging equipments, thus to raise accuracy of feedback. The traditional length gauge sensor used for positioning can generally reach a precision of 1mm, but with a serious drift of temperature, which affects precisely positioning of objects. Instead, a laser range finder can be achieved less than 0.1mm, and as a non-contact measuring instrument, it is easy to install, as well as high precision and low temperature drift.

Development process of laser rangefinder is introduced briefly in this paper. Working principle of laser rangefinder and ranging equation is also discussed. Relationship between signal to noise ratio (SNR) and ranging capacity is analyzed. By using spectral filtering, spatial filtering, and cumulative technique, ranging distance can be improved. The maximum of ranging distance can reach 1000m in good weather conditions. Ranging accuracy of laser rangefinder is decided by forefront of laser pulse, response time of APD and bandwidth of amplifier. It is about 1m.

A compact laser rangefinder has been developed, which incorporates a sealed-off pulsed CO(2) TEA laser and uses direct (i.e., nonheterodyne) detection. This device is essentially eye safe and benefits from the superior atmospheric transmission at 10.6-microm wavelength. Design parameters are presented and illustrated, and system performance is discussed.

Recent advances in Vertical-cavity Surface-emitting Laser (VCSEL) efficiency and packaging have opened up alternative applications for VCSELs that leverage their inherent advantages over light emitting diodes and edge-emitting lasers (EELs), such as low-divergence symmetric emission, wavelength stability, and inherent 2-D array fabrication. Improvements in reproducible highly efficient VCSELs have allowed VCSELs to be considered for high power and high brightness applications. In this talk, Aerius will discuss recent advances with Aerius' VCSELs and application of these VCSELs to miniature optical sensors such as rangefinders and illuminators.

The laser proximal fuse is used to detect objects with laser beam. It can conduct a comprehensive survey of objects and has the characteristics of good anti-interference, accurate directionality, and high precision. Aiming at some common problems of proximity-fused laser rangefinder, a new echo receiving circuit of the system was designed in this paper. What's more, the performance of the system were simulated and analyzed in-depth. The key parameter was met with the system requirement. The designed echo receiving circuit was used in practical laser ranging system.

This paper deals with the application of computer vision to mining automation. In particular, it presents results from an on-going research project investigating the automation of the rock-breaking process, a process typical of underground hardrock mining. The objective of this research is to investigate the use of computer vision to identify and locate the oversized lumps remaining on a grizzly (metal sieve) after blasting, for the secondary rock-breaking operation. Range images of rocks are acquired in our laboratory using the NRCC/McGill laser rangefinder. Rock-pile images are segmented into parts (rocks) based on their surface characteristics. Finally, superquadric models are fit to the segmented range data to characterize the 3D shape of each rock.

This paper presents design, implementation and testing of a communication module for a laser range finder with integrated positioning system (GPS). Range finders are widely used in military but also civil applications like topography. The idea was to upgrade a standard laser rangefinder device with position information subsystem and to have radio transmission of distance and position information. An interface module between rangefinder and GPS module, on one side, and data processing unit, on the other side, was developed in order to meet these requirements. The communication as well as GPS modules are placed into the rangefinder case. Software tools were developed for accessing rangefinder data from Windows-based personal computers.

We propose a support system of range data acquisition by a laser rangefinder for wide area outdoor modeling in order to reduce un-observed portions of generated model. The system presents the operator a recommendation degree map which illustrates recommendation position of acquisition of range data in the objective area. The operator decides a next acquisition position in consideration of movement distance of sensor system and recommendation degrees of the map. The recommendation degree is computed by measurement density as the index. The recommendation degree at a position is given by the difference between measurement density acquired by rangefinder and measurement density estimated by the system in reachable area of the laser beams. The reachable area of the laser beams is estimated by using a 3D model generated from the acquired range data. The system computes the measurement density by the reachable area of the laser beams. The recommendation degrees in the objective area are computed by the model generated from range data whenever a range data is acquired. Moreover, the system judges whether overlapping portions of the range data can be acquired for the registration by ICP algorithm from a work area which the sensor system can enter., Videometrics IX , Jan 28, 2007 , San Jose, CA, USA

Raytheon's AN/ASQ-228 Advanced Targeting Forward-Looking Infrared (ATFLIR) Pod features state-of-the-art mid-wave infrared targeting and navigation FLIRs, an electro-optical sensor, a laser rangefinder and target designator, and a laser spot tracker. ATFLIR is fully integrated and flight tested on all F/A-18 Hornet/Super Hornet models, approved for full-rate production and is forward deployed, supporting US. fleet operations worldwide. This paper will present ATFLIR status and a summary of future plans.

A Global Laser Range Profilometry (GLRP) System has been developed at the Naval Surface Warfare Center, Carderock Division (NSWCCD) for the measurement of three dimensional wave surfaces. A laser diode array consisting of 100 diodes operating at 650nm with an energy output of 3.5 mW was used to illuminate the wave surface seeded with fluorescent dye at various points in the Miniature Water Basin (MWB) facility at NSWCCD. A CCD camera located above the water surface recorded successive images of the laser array at 30 frames per second. Image processing techniques were used to locate the centroid of the laser array diode locations in the collected images. Calibration images were taken at various calm water heights in order to convert the image centroid locations to real coordinates. Two- and three-dimensional results are presented, along with error analysis of the GLRP system and comparison to flow visualization. A discussion of possible applications and planned future work is also presented in this work.

This paper describes a proof-of-concept experiment using a prototype system in which laser range data are used for detecting missing teeth of a mining shovel used in the surface mining industry. A 3-D CAD model of the tooth-line is first built graphically. A laser rangefinder on a pan-tilt unit is then used to scan the tooth-line and acquire 3-D data of the shovel teeth. The 3-D data are processed to arrive at a description of the tooth-line in terms of its features, and this description is compared and matched with the CAD model of the tooth-line to detect any abnormal conditions in real-time.

Here we consider an autonomous navigation system for the International Ground Vehicle Competition (IGVC) Navigation challenge competition. This event is for a vehicle to autonomously travel from a starting point to several target destinations and return to home base only by the target coordinates. This paper describes how vehicle named Amigo2002 by Hosei University was implemented by combining DGPS. Gyro and laser rangefinder.

A portable laser rangefinder, capable to measure ranges up to 1,200 m, implies the measurement of time intervals ranging between some tens of ns and some tens of μs with an accuracy of less than 1 ns. Taking into account that laser pulse rate is low (1...10 kHz) our solution was the time expansion in few stages followed by a classical time interval measurement. We actually expanded the time range 100 ns ÷ 10 μs into the range 25 μs ÷ 2.5 ms and the new time interval is measured using a 5 MHz quartz driven clock. The measurement accuracy is then 0.42 ns.

This paper primarily studies the project of adjustment and examination of optical axis’ parallel of a visual device, especially to laser rangefinder’s three axes’. One way which uses either big aperture collimation mirror of off-axis paraboloidal mirror or of coaxial paraboloidal mirror is put out and outdoors examination method is also given. Use a tool that can measure the parallelism of optical axis.

The mini pulse laser rangefmder (LRF) uses semiconductor laser as its source. This kind of LRF has property of safe, small size and low cost. It can be applied in sports and some filed of engineering just like wire layout. To extend its application field, the measurement parameter, which is now 1km in maximum range and 1m in accuracy at one measurement, need to be improved. The raise time of pulse can be more sharp, the speed response of receiver can be more quickly and the efficient arithmetic should be taken.

Due to unsymmetrical irradiance pattern of most diode lasers combined with inherent astigmatism diode laser based devices are not trivial to classify. In absence of non-standard collimation optics such as cylinders, wedges, special fibres etc. used to reduce inherent astigmatism and to circularize the laser beam, cross section geometry of such a collimated beam may vary substantially going from near field to far field.This adds to complexity of classification procedure in the following manner: • angular subtense has to be evaluated at several distances in front of the device and • radiant exposure in the near field doesn’t necessarily behave as a uniform function of increasing distance from the device Due to unsymmetrical irradiance pattern of most diode lasers combined with inherent astigmatism diode laser based devices are not trivial to classify. In absence of non-standard collimation optics such as cylinders, wedges, special fibres etc. used to reduce inherent astigmatism and to circularize the laser beam, cross section geometry of such a collimated beam may vary substantially going from near field to far field.This adds to complexity of classification procedure in the following manner: • angular subtense has to be evaluated at several distances in front of the device and • radiant exposure in the near field doesn’t necessarily behave as a uniform function of increasing distance from the device