Automatic Range Finding Bow Sight

With the growing popularity of archery, a system designed to help an archer achieve the best shot possible becomes necessary. The Automatic Range Finding Bow Sight is a system that consists of a single pin sight controlled by a servo motor. The servo motor controls the sight pin by rotating a drive wheel that will move the pin up or down. The sight pin movement is based on a reading obtained by a built-in rangefinder and speed data input by the user. This data will then be compared to programmed lookup tables in order to find the appropriate pin position. After the sight pin has been adjusted, the user should be confident they will hit their target. Rangefinder will quickly obtain distance when triggered The servo motor will accurately adjust the sight pin up or down Interpolation between lookup table rows will ensure accurate movement

Gnome on the range: finding the hypertextual narratives in ancient wisdom texts

In this paper we present the Sharing Ancient WisdomS (SAWS) project. Working with wisdom texts, or gnomologia, the project aims to produce an enhanced digital scholarly edition of the collected manuscripts which both makes the Greek, Arabic and Spanish texts available and demonstrates the hypertexual nature of these texts. By positioning the texts as collections of sayings, of which a given manuscript only shows one narrative path, we demonstrate how a hypertextual approach allows us to explore alternate narrative paths within and across the texts and support researchers as they study the context, significance and transmission of the wisdoms within these works

Range Finding with a Plenoptic Camera

The plenoptic camera enables simultaneous collection of imagery and depth information by sampling the 4D light field. The light field is distinguished from data sets collected by stereoscopic systems because it contains images obtained by an N by N grid of apertures, rather than just the two apertures of the stereoscopic system. By adjusting parameters of the camera construction, it is possible to alter the number of these `subaperture images,\u27 often at the cost of spatial resolution within each. This research examines a variety of methods of estimating depth by determining correspondences between subaperture images. A major finding is that the additional \u27apertures\u27 provided by the plenoptic camera do not greatly improve the accuracy of depth estimation. Thus, the best overall performance will be achieved by a design which maximizes spatial resolution at the cost of angular samples. For this reason, it is not surprising that the performance of the plenoptic camera should be comparable to that of a stereoscopic system of similar scale and specifications. As with stereoscopic systems, the plenoptic camera has its most immediate, realistic applications in the domains of robotic navigation and 3D video collection

Vehicle Based Laser Range Finding in Crops

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

A New Range Finding Method Using a Varifocal Mirror

A new range finding method is proposed in this paper which makes use of a varifocal mirror. The three-dimensional object space is first discretized into a sequence of spherical shells with a specially designed nonlinear vibrating varifocal mirror. These discrete spherical shell images are then recorded by a video camera. A deblurring algorithm is introduced in this paper which is used to remove the blurred components in the images. Different depth ranges can be obtained by controlling the vibration amplitude and the direct current component of the driving wave for the varifocal mirror. The depth accuracy is adjusted by varying the vibration period of the varifocal mirror. This range finding technique can be made real time by increasing the frame frequency of the camera

A Real-time Range Finding System with Binocular Stereo Vision

To acquire range information for mobile robots, a TMS320DM642 DSP-based range finding system with binocular stereo vision is proposed. Firstly, paired images of the target are captured and a Gaussian filter, as well as improved Sobel kernels, are achieved. Secondly, a feature-based local stereo matching algorithm is performed so that the space location of the target can be determined. Finally, in order to improve the reliability and robustness of the stereo matching algorithm under complex conditions, the confidence filter and the left-right consistency filter are investigated to eliminate the mismatching points. In addition, the range finding algorithm is implemented in the DSP/BIOS operating system to gain real-time control. Experimental results show that the average accuracy of range finding is more than 99% for measuring single-point distances equal to 120cm in the simple scenario and the algorithm takes about 39ms for ranging a time in a complex scenario. The effectivity, as well as the feasibility, of the proposed range finding system are verified

A Comparative Analysis of IEEE 802.15.4 Adapters for Wireless Range Finding

ZigBee wireless networks have become increasingly prevalent over the past decade. Based on the IEEE 802.15.4 low data rate wireless standard, ZigBee offers low-cost mesh connectivity in hospitals, refineries, building automation, and critical infrastructure. This thesis explores two ZigBee Received Signal Strength Indicator (RSSI)-based rangefinding tool sets used for assessing wireless network security: Z-Ranger and Zbfind. Z-Ranger is a new tool set developed herein for the Microchip Zena Wireless Adapter that offers configurable distance estimating parameters and a RSSI resolution of 256 values. Zbfind is an application developed for the Atmel RZUSBstick with no configurable distance estimating parameters and a RSSI resolution of 29 values. The two tool sets are evaluated while rangefinding four low-rate wireless devices indoors and two devices outdoors. Mean error is calculated at each of the 35 collection points and a 99% confidence interval and p-Test are used to identify statistically significant deviations between the two tool sets

Odometry Correction of a Mobile Robot Using a Range-Finding Laser

Two methods for improving odometry using a pan-tilt range-finding laser is considered. The first method is a one-dimensional model that uses the laser with a sliding platform. The laser is used to determine how far the platform has moved along a rail. The second method is a two-dimensional model that mounts the laser to a mobile robot. In this model, the laser is used to improve the odometry of the robot. Our results show that the one-dimensional model proves our basic geometry is correct, while the two-dimensional model improves the odometry, but does not completely correct it