Every day of your computing life, you reach out for the mouse whenever you want to move the cursor or activate something. The mouse senses your motion and your clicks and sends them to the computer so it can respond appropriately. An ordinary mouse detects motion in the X and Y plane and acts as a two dimensional controller. It is not well suited for people to use in a 3D graphics environment. Space Mouse is a professional 3D controller specifically designed for manipulating objects in a 3D environment. It permits the simultaneous control of all six degrees of freedom – translation rotation or a combination. . The device serves as an intuitive man-machine interface.
The predecessor of the spacemouse was the DLR controller ball. Spacemouse has its origins in the late seventies when the DLR (German Aerospace Research Establishment) started research in its robotics and system dynamics division on devices with six degrees of freedom (6 dof) for controlling robot grippers in Cartesian space. The basic principle behind its construction is mechatronics engineering and the multisensory concept. The spacemouse has different modes of operation in which it can also be used as a two-dimensional mouse.
How does computer mouse work?
Mice first broke onto the public stage with the introduction of the Apple Macintosh in 1984, and since then they have helped to completely redefine the way we use … Read the rest
Now days there are several navigation systems for positioning the objects. Several research efforts have been carried out in the field of Six Degrees Of Freedom estimation for rendezvous and proximity operations. One such navigation system used in the field of Six Degrees Of Freedom position and attitude estimation is the VISion based NAVigation system. It is aimed at achieving better accuracies in Six Degrees Of Freedom estimation using a more simpler and robust approach.
The VISNAV system uses a Position Sensitive Diode (PSD) sensor for 6 DOF estimation. Output current from the PSD sensor determines the azimuth and elevation of the light source with respect to the sensor. By having four or more light source called beacons in the target frame at known positions the six degree of freedom data associated with the sensor is calculated.
The beacon channel separation and demodulation are done on a fixed point digital signal processor (DSP) Texas Instruments TMS320C55x  using digital down conversion, synchronous detection and multirate signal processing techniques. The demodulated sensor currents due to each beacon are communicated to a floating point DSP Texas Instruments TMS320VC33  for subsequent navigation solution by the use of colinearity equations.
Among other competitive systems  a differential global positioning system (GPS) is limited to midrange accuracies, lower bandwidth, and requires complex infrastructures. The sensor systems based on differential GPS are also limited by … Read the rest
Steganography comes from the Greek and literally means, “Covered writing”. It is one of various data hiding techniques, which aims at transmitting a message on a channel where some other kind of information is already being transmitted. This distinguishes steganography from covert channel techniques, which instead of trying to transmit data between two entities that were unconnected before.
The goal of steganography is to hide messages inside other “harmless” messages in a way that does not allow any “enemy” to even detect that there is a second secret message present. The only missing information for the “enemy” is the short easily exchangeable random number sequence, the secret key, without the secret key, the “enemy” should not have the slightest chance of even becoming suspicious that on an observed communication channel, hidden communication might take place.
Steganography is closely related to the problem of “hidden channels” n secure operating system design, a term which refers to all communication paths that cannot easily be restricted by access control mechanisms. In an ideal world we would all be able to sent openly encrypted mail or files to each other with no fear of reprisals. However there are often cases when this is possible, either because the working company does not allow encrypted email or the local government does not approve of encrypt communication (a reality in some parts of the world). This is … Read the rest
Ever since the development of the ENIGMA (the first digital computer), computers have inspired our imagination. In this period came the World War II code breaking machine designed by Alan Turing, and Von Neuman’s ENIAC which can be called dinosaurs compared to present day PCs. In the earlier days, computers were so huge that it took an entire building, or at least a floor to occupy one. Computers of that era were very slow by today’s standards. In the non-ending struggle to increase computing speed, it was found out that speed of electricity might become a limiting factor in the speed of computation, and so it was a need to lessen the distance that electricity had to travel in order to increase the computing speed. This idea still holds true in modern computing.
By the 1970s, computers grew fast enough to process an average user’s applications. But, they continued to occupy considerable amount of space as they were made of solid blocks of iron. The input was done by means of punch cards, and later came the keyboard, which revolutionalized the market. In 1971 came the 4004, a computer that was finally small in size. The programmability of these systems were quite less. Still, computers had to be plugged directly in to AC outlets, and input and output done by punch cards. These computers were not built keeping users in … Read the rest