INTRODUCTION/OBJECTIVE: Our project aim is, to create a sensor package that can be used to…
The proposed project is a multi-functional measurement tool. It utilises a custom laser ranger, along with an inertia meter and a liquid crystal display in a compact package. It allows the user to interactively calculate domains in various ways, including remote point to point and distance measurements, area and volume of a room. The intuitive user interface will improve the functionality of the product, allowing the operator to easily control the device and to convert between units, to measure angles and to monitor battery life. The purpose of the project is to offer an improved alternative to an already existing device at an affordable price.
The features of our product are:
A good solution to all of the problems will be a low cost, low power consumption, small package device, which can provide precise measurements of all problems defined above. It is important to develop such product, because although these technologies exist separately there is no unified solution to all of them at an affordable cost.
In order to obtain remote measurements we will design a custom laser ranger. Implementing a small power supply circuit and laser driver which will modulate a GDL-6005 device. This laser is a green 532nm wavelength which is in the visible light spectrum. It was chosen because of its brightness, easier detection and more intuitive user operation. The modulated laser beam is then captured by a small CMOS camera positioned at a precise position with respect to the laser module. The camera will capture several consecutive images, which will be filtered and compared by the device. When the position of laser spot is calculated with respect to the center of the image, the angle between the line of sight and the direction of camera with be approximated. This process will require fine calibration for every specific camera of choice. When the angle (theta) and the base distance (h) are known the distance (D) between the measuring device and the target could be triangulated.This will be sufficient to obtain a single distance measurement. The device will also implement a 3 axis tilt compensated magnetometer. A similar process could be used including the readings from the tilt sensor in order to calculate the distance between any two points in 3D domain. The same sensor will also be used to turn the device into a level meter. Non contact thermal measurements will be obtained using MLX90614 IR thermometer. When the device is turned on the NXP LPC1768 mbed module will remain in standby mode and ‘listen’ for input from the user. It will then execute a routine accordingly. The communication between the controller and peripherals depends on their design. For this prototype most of the peripherals are integrated as external shields, connected to a main board with a control unit, rather than a completely custom design on a single pcb. The reasons behind this decision are time constraints and complexity of a completely custom system.
Ivan Lazarov, Dimitar Borisov, Eduard Kalfov, Ovidiu Popoviciu and Ahmed Janahi