DornerWorks Case Studies

Provide the necessary software without the advantage of utilizing a real simulation environment. Improve the performance of the system by developing a faster network protocol stack interfacing to the SCOE that eliminated unnecessary message copies within the stack.

DornerWorks developed software improvements for Civil Holds to dynamically resize holding patterns based on planned fly time. This improved the old method where there was a fixed-size pattern with no guarantee the pilot would be in position to exit the holding pattern at the desired time. Another critical area where our engineers contributed was in its “mark points” feature. This is a part of the GPS system that marks the present aircraft position as a reference for future use. These positions are stored in a database and can then be used for future flight planning operations. Additionally, our engineers improved the “alternate destination” feature. This feature calculates alternate destinations, including the time and the remaining fuel required to land thereby improving the older system by adding the capability to activate the alternate plan at the press of a button. Each of these features was tested with flight simulation software.

Interfacing different hardware elements for the new Pave Pillar Common Module / Integrated Rack technology of the Advanced Tactical Fighter (YF-23A).

Our engineers modified and extended the Unisys Maintenance Controller executive software to be used by the SCI Bulk Memory Module (BMM), including the memory control functions. The extensions included a new interface to the PI-Bus control chip. They rewrote SITE bus handler drivers, improving their efficiency by a factor of two. They also integrated the PI bus command and ATP processing into the executive and simulated all the BIT tests. They also integrated the Application Test Program software for the ATF Common Module BMM and implemented debug software downloaded to the SCI BMM. They were then involved with testing the BMM hardware and the BMM ATP software. The system was developed according to MIL-STD-2167.

In developing a system that allows patching of code without compiling in the testing environment.

On the P-8A our team members were instrumental in developing and using a simulator for the interaction of the cockpit and weapons of the aircraft to the stores computers, a simulation of the autopilot that allowed a large number of different conditions to be checked in a limited amount of time, and developing a system that allows patching of code without compiling in the testing environment.

The simulator interfaced with the Controller Area Network (CAN) of each of the two stations, and provided the CAN data to emulate the data that the Sonobuoy launchers would provide if connected. This system used a National Instruments Controller Card in a PCI slot of a PC. The simulator could send an assortment of data from the launchers to the station to ensure that it handled all of the scenarios tested, as well as reporting of values in fields correctly. The simulator was written using the C++ .NET framework 1.1. Our engineers developed a set of .NET libraries to interface with the National Instruments Controller Card. The GUI for the system provided an interface to set values in each of the messages as well as change settings on the National Instruments Controller Card. The GUI allowed the user to interface with each of the six launchers, individually organizing them by fields stated in the ICD.

Updating the hardware and modification of the associated software.

Our engineers worked on the Stores Management System Upgrade (SMUG). This included a processor board containing a PowerPC processor, non-volatile memory, and watchdog timer; a rugged power supply card; and I/O cards including video I/O, analog I/O, digital discretes, high-voltage fusing outputs, and 1553 communication. Our engineers also managed the test and integration team to incorporate, debug, and validate the upgraded system on the F/A-18 simulator and automated test equipment. Because the upgrade included replacing an obsolete, custom processor that used little-endian ordering with a the new PowerPC processor that used big-endian ordering of data, significant changes were required in the low-level software drivers and test code. Our ability to work with where the software and hardware met, was critical to the project’s success.

Since 2005, DornerWorks has played an important role in several design phases of the Boeing 787 Dreamliner. Below are highlights of this project.

To develop simple and cost effective SAM test equipment widget allowing simulation of error and fault conditions within the airflow system.

We provided the customer with a simulated environment in order to test the 787 Cabinet Airflow Mechanisms and sensors including the main cabinet and mini-cabinet that housed the GPMs and PCM (managed the Airflow through the cabinets to prevent damage from overheating). The system included a single board computer (PIC 8-bit processor). The black box interfaces included pressure input, voltage levels, and current level GPIO PWM. They developed a SAM test equipment widget allowing simulation of error and fault conditions that were otherwise difficult or costly to test within the airflow system. The SAM widget also simulated the output of the airflow equipment during nominal conditions if desired.

In another phase of the 787 Dreamliner, we were asked to create a system definition and the resulting VHDL and identify discrepancies between the board layout and the simulated board layout.

The Control System Board is a dual CPU, dual FPGA, and dual ASIC board running full ARINC653 partitioning used as the main computing resource for the entire aircraft. During development, our expertise in Virtutech Simics enabled our engineers to emulate the AFDX communications and identify and resolve issues in the software. Our testing led to us improving several key pieces of the software including significant enhancement to the ARINC-665 data-loader.

Our team members were instrumental in developing a redundant fault tolerant design, general purpose DMA engines, and a UART, all targeted for an ARINC 653 partitioned operating environment. We were also the system architects for the multiple CPU interface for the ASIC. Context specific hardware exception handling to support/ allow different behaviors. ISR rewritten to allow AltiVec handling for some partitions and not for others.

Proper routing of exceptions into AE653 partitions and ensuring the guaranteed separation of the partitions was another design aspect. Designed into the AE653 was a mechanism to ensure that the module Operating System and health monitoring application wee running by implementing a two level software watchdog timer system. Our engineers expert knowledge of BSP and AE653 ensured it did not impact system timings. We performed the required analysis of OS and unpublished data structures to identify key parameters and areas then work with WindRiver to ensure stability of these structures.

Additionally, tests were written by our staff to ensure DO-178B level A compliance and DER acceptance of the changes. Data on the 787 Dreamliner V&V shows that DornerWorks produced very high quality tests, resulting in a first pass correctness rate of 96% compared to a rate of 52% produced by some of our competition. Our quality yields the lowest overall cost, saving around 30% when compared to others who have less effective systems.

“The members of your team are consistently highly regarded. That is why we do not hesitate to send difficult technical tasks to your team. I am not sure what you guys are doing to attract the top talent, but we sure like the results.”

—Engineering Manager, major aviation company

Develop a motor control software system using independent flap position sensing.

DornerWorks engineers successfully developed a Trapezoidal Control of a BLDC motor using Hall effect sensors for speed and position control. It also used RVDT excitation for flap position sensing that was done in parallel with motor control sensing for independent verification of the flap positioning. We performed requirements development, software architecture (including software prototyping), software implementation, and software verification (high-level and low-level). This included all necessary BIT and communications between controllers and Ground support Equipment. This project demonstrated DornerWorks to effectively move commercial motor control technology into a flight worthy DO-178B system.