Closed Loop
We use the term "closed loop" to describe a simulator that is supplied with dynamic vehicle trajectory data - time, position, velocity, acceleration, jerk, attitude, and attitude-rate - real time using an external high speed data interface such as GPIB, Ethernet, or ScramNet. These systems are typically for military applications in which the data transfer rate is high and the data transport delay is small. Since the closed loop system is usually used as a component within a comprehensive test suite, timing and data synchronization are of paramount importance. Our LabPro-CL was designed specifically for the closed loop application. Our software controlled 1-PPS output, large input data buffer, and ability to handle asynchronous data input, make the LabPro-CL an invaluable asset in the laboratory. Applications perfectly suited to the LabPro-CL include, training systems, multi-sensor weapons systems, or any systems that were designed for the Stel-7200 series constellation simulator. The LabPro-CL provides 10 -14 simultaneous GPS satellite signals in one of two configurations:
In either arrangement, the LabPro-CL accepts modeling and input trajectory data from the Remote-User to construct the appropriate GPS RF outputs. Simply said, the Remote-User models the vehicle, the LabPro-CL models the GPS by performing range computations and data computations. The dialog between the LabPro and Remote-User is implemented in one of the following real-time interfaces:
(Note: the GPIB-master closed loop mode is a drop-in replacement for the Stanford Telecom 7200 series constellation simulators. If your system works with the STel, it will work with ours!. The following figure schematically illustrates the LabPro-CL and User.
The LabPro-CL is the perfect simulator for the multi-sensor test laboratory. Our systems growth potential - capability wise - will prove to be an invaluable asset in the Lab. Our modeling and implementation provides a navigation performance test capability resulting from factors such as, Vehicle dynamics, Minimum signal level, Jamming, Control segment errors, GPS edge conditions. Our 1-PPS implementation and synchronization allows for acquisition testing such as, Time-to-first-fix, Signal acquisition, Jamming. Through the use of auxiliary interfaces such as GPIB, Ethernet, 1553, Arinc429, RS232, Differential, and our Multi-Function I/O Card (MFIO), the LabPro-CL can communicate directly to the GPS receiver under test or to other sensors that interface to the receiver under test such as: Inertial Measurement Units, System timing, Instrumentation Port, Jammers, and other sensors.
The type of test system the LabPro-CL is designed for is extremely powerful, and at the same time, very complex. We have worked directly in all aspects of the setup and operation of this type of lab. Give us a call and we can arrange a demonstration or provide additional literature to more comprehensively describe the capabilities of this system and our company. |
