At Kashmir World Foundation, we design aircraft to support the protection of endangered species. Nearly all of our aircraft are of a blended wing body design, optimized for efficiency and stability, and operating on ArduPlane. Currently, we’re developing a new aircraft intended for patrol missions over the Himalayas, where it will face high and variable winds. This design is being optimized not only for efficiency but also for agility.
As part of our development process, we are stepping through a detailed analysis of efficiency, stability, and agility using ArduPilot SITL. Unfortunately, we’ve run into a snag.
We’re working on integrating our latest Blended Wing Body aircraft into ArduPlane SITL using JSBSim as the Flight Dynamics Model. The aircraft has two pusher engines mounted symmetrically on either side of the centerline. Currently, only the left engine is producing thrust during simulation.
The FDM was created in JSBSim using aerodynamic parameters derived from OpenVSP. Our ArduPlane .parm file is based on the default JSBSim SITL configuration. Engines are configured on Servo 3 (Left Engine) and Servo 5 (Right Engine)—please confirm if this assignment is correct.
We compiled ArduPlane SITL from the latest source. We’ve tried disabling and reversing the outputs on Servo 3 and Servo 5 to verify thrust behavior. The Left Engine responds as expected. However, the Right Engine does not produce any thrust regardless of configuration.
Questions:
- Has anyone encountered a similar problem when integrating JSBSim with ArduPlane in a dual-engine configuration?
- How does ArduPlane recognize engines from a JSBSim FDM XML file?
- What are the required steps—starting from defining the FDM and ending in simulation—for ArduPlane to properly simulate two engines?
We’ve attached both the .parm parameter file and the JSBSim FDM in .txt format for reference.
Any advice or experience shared would be greatly appreciated.
Thanks, Ron / Team Pegasus / Kashmir Robotics / Kashmir World Foundation
ER_W2.param (24.9 KB)
ER_W2_FDM.txt (17.6 KB)