Archive for the ‘System Engineering’ Category

Vectioneer Motion System Design Software

Motion System Design Software

Here are some more details on our motion system design software. Vectioneer presented the current status at last week’s Blender Conference.

Below you can see a screencast of the use of our new Motion System Design software. Our in-house developed simulation software is extended with a Blender frontend for easy user interaction.
With the software it is possible to intuitively design any parallel mechanism. The software calculates important system metrics on the fly, so it becomes very easy for the designer to optimize the design.

The video shows how the parameters of a Hexapod System, such as joint locations and payload center of gravity location, are changed to arrive at an asymmetric Hexapod design. At the end a detailed report is generated describing the system design and the requirements for all subsystems such as gearboxes, servomotors, joints, worst case forces.

The video below shows an animation of 3DOF motion system design, where the system is put in a certain pose when the brakes on the actuators are released and the system freefalls to a steady state. All system dynamics are modelled including payload and drive system inertias and coulomb friction.


Motion Design Software

Sneak peek: our in-house developed Motion System Design Software

Vectioneer has developed a revolutionary intuitive design tool to design parallel mechanisms such as Hexapod or Crank Driven Motion Systems. The algorithms that provide the kinematic and dynamic modeling are written completely from scratch and are implemented in Python 3. The software allows to change designs very quickly and calculate system performance and component specifications on the fly. This way it is possible to show the effect of design changes in real-time.

Using this dedicated software the design process is much more efficient than using regular CAD packages to model and simulate the system in. We can provide our customers with a new motion design in mere hours, including a complete report of all the kinematic and dynamic requirements on the system components, such as maximum servo motor torques and velocities, average power consumption, worst case forces, maximum joint angles, motion enveloppe drawings, etc.

Although largely complete, the software is still under heavy development to add more features such as genetic algorithms to search for optimal mechanism solutions automatically.

For the user interface we use our favorite free software, Blender, which turned out to be perfect for the job. It provides a fast and stable platform and has an excellent interface to our own Python code. As an extra it can render amazingly realistic pictures and animations of our designs to impress our customers with.

The software is not for sale, but is used to design new custom motion systems for our customers.

Please contact us for more information.


Flying the Joint Strike Fighter Engineering Simulator

While I was at Lockheed Martin in Forth Worth, Texas, earlier this year I got the chance to fly the Joint Strikefighter (F35 Lightning II) Engineering Flight Simulator. Since I was part of the design team (System Engineer) for the Motion System of this unique flight simulator I know this system quite well and this was actually the second time that I got to fly it. Of course the cockpit was partly switched off for security reasons, but primary flight controls where available and kept me busy enough.

Normally, fighter simulators do not use motion systems, since the accelerations in the aircraft cannot nearly be reached by a normal hexapod motion system. The F35 however also comes in a version with short takeoff and vertical landing capabilities (STOVL), where the accelerations are much more moderate. The vertical landing part is also a very critical phase in the flight envelope, which requires the avionincs to work together with the pilot to stabilize the aircraft. To test various avionics setups in the simulator and accurately involve the pilot in this closed-loop experiment, the F35 Engineering Simulator does require a very fast motion system.

The capabilities of the motion system are substantial, especially the high roll rates of up to 40 degrees per second and the large excursions required an optimized hexapod design. Engineering such a high performance hydraulic motion system also brings particular challenges, such as the extremely high accelerations that can occur when the servovalves close suddenly. Therefore, for this system a new servovalve setup was developed to reduce the peak forces while keeping the nominal system reponse at the desired levels.

Flying this simulator can only be described as being awesome. I consider myself very lucky to have flown it a couple of times and I feel proud to have designed this angry beast of a motion system.

(Thanks to Lockheed Martin for providing this picture)


VTI-SimIV

Motion System Tuning of the VTI Driving Simulator IV

Vectioneer was hired to perform motion system tuning of the VTI Driving Simulator IV in Gothenburg, Sweden. Sim IV is the latest of VTI’s driving simulators and one of the most advanced in the world. It features an exchangeable cabin design for truck or passenger car cabins, a large Motion System from Bosch Rexroth which can generate realistic motion cues to the driver, a nine channel visual system with a cylindrical screen, VTI’s in-house developed image generator, sound system with a subwoofer capable of simulating vibrations, vehicle dynamics models and traffic simulation. VTI developed the simulator in-house with its industry partners.

The simulator is used for research into vehicle systems, such as trucks or cars. Currently is setup for truck simulation and will be used to perform experiments with driver assistance systems.

Vectioneer was hired to tune the motion system of the simulator to maximum performance and perform the final acceptance testing with VTI. Also Vectioneer assisted VTI with the Motion Cueing algorithms and trained the VTI researchers in the use of Rexroth’s Motion Cueing software.

Here are some interesting links about the VTI Driving Sim IV, some of which are only available in Swedish (but the images and videos are worthwhile):


Motion Cueing Tuning of the Tongji Driving Simulator

Motion Cueing Tuning of the Tongji Driving Simulator

Vectioneer provided its services during the Motion Cueing Tuning of the Tongji University advanced Driving Simulator in Shanghai, China. The simulator is one of the largest full motion driving simulators in the world and the first of its kind to be in use in China. The simulator has been designed and built by french company Oktal, who have already delivered a number of similar Driving simulators in Europe (Renault, Peugeot-Citroen, CTAG). The unique high performance Motion System has been designed and built by Bosch Rexroth in The Netherlands.

The Tongji University High Performance Driving Simulator

This simulator will be used by Tongji University to conduct research into automotive systems and especially into man-machine interaction. Using this simulator the University will have the capability to generate different driving scenarios using Oktal’s SCANeR software and evaluate human performance in the simulated environment. For instance it is possible to test driver assistance systems such as adaptive cruise control before even a prototype of such a system is built.

Vectioneer was contracted to perform initial tuning of the Motion Cueing Algorithms for the Simulator. Motion Cueing Algorithms provide the translation between the motion of the real vehicle and the motion of the simulator. In a simulator this translation is always necessary because of the limited workspace of a simulator; a simulator just cannot move you over the same distance as a real vehicle would because it has to stay in the building. This provides a challenge, since for the driver to me fully immersed in the simulation his/her perception of motion in the simulator should be the same as in the real vehicle (or at least as close as possible). The many parameters of the Motion Cueing Algorithm require tuning to the specific properties of the simulated vehicle, the simulated scenarios and the properties of the simulator hardware itself.

Philippe is tuning the Motion Cueing Algorithms with David Charondière (Oktal) in the car

The Motion System of the Tongji Driving Simulator consists of a standard Hexapod with a payload capability of 2500kg and an additional X/Y motion system to extend the range of longitudinal (X) and lateral (Y) motion capabilities. These additional motion capabilities are a huge plus for a driving simulator, since this means that longitudinal and lateral accelerations which are so important in car handling qualities can be simulated much better than with just a Hexapod motion system. The additional stroke that the X/Y system provides is 20 meters in X and 5 meters in Y.

The Tongji University High Performance Driving Simulator as seen from the control room

The Tongji Driving Simulator is now in the final stage of commissioning. It will be available for the Tongji University staff very soon.