Canopy Newsletter 11 — Jul 2019

Tired of running thousands of straight sims to figure out how to rebalance your car? We might have the solution for you:

Dynamic Constraints

When comparing laptime across different setups, strictly speaking one should rebalance the car. The previous procedure to do this was to run a number of pre-sims to figure out what changes were required to rebalance the car, then add these to the exploration. Now the car can automatically be rebalanced for ride heights, aero and mechanical balance.

Constraints rebalance the car using straight sim at a user specified speed. The following adjustments can be made:

• Front or rear ride height targets at a given speed.
• Aerobalance modification by trimming aFlapF, front ride height or rAeroBalanceUserOffset.
• Mechanical balance and roll stiffness target by changing front/rear anti roll bars.

After the constraints have been applied the simulation will run as normal. You can see what trims were made by checking the scalar results or by staging/saving/comparing the newly modified car, which is saved with the study results.

We’re hoping that this feature has great time saving potential, but we’re aware that it won’t cover all of the rebalancing requirements for your specific car. Get in touch if you’d like us to add additional constraints.

Sub Limit Sim

When trying to extract edge of envelope car performance from Limit Sim, it has been noted that since the car is balanced on a knife edge there can be relatively large changes in car state for relatively small changes in parameters. To get around this we have released a new simulation type which will return the car state for a user specified series of vCar-gLat-gLong operating points. This enables you to examine the car state in this sub limit condition which should give more consistent results. Since there are infinitely many car states below the limit of performance, we use the following equation to pick a low slip solution: sum(rSlipTyreXX² + aSlipTyreXX²).

Worksheet Updates

We’re really happy to see people using Worksheets to organise their simulations, DiL and car data. We’ve made a number of enhancements to improve performance:

• Sheet & Car Ownership: To stop you accidentally modifying someone else’s work you have to take ownership of a worksheet before you can modify it.
• Shortcut button: A link at the top right of the page to the list of worksheets.
• Shortcut keys: Arrow keys to move selected cell, cut, copy, paste, delete, shift, ctrl, enter, undo and redo.
• Undo & Redo: Go back in case of accidental modification.
• Worksheet metadata: Somewhere to jot down your notes, or add custom properties for organising worksheets.
• Clone sheet: Duplicate a worksheet template for standard analysis.
• Right click: To access list of commands.

Did you know…

• A stick-slip diff model has been added for the DiL model and can be parameterised using Virtual 4 Post Rig.
• Push To Pass option in the track enables you to specify an sLap starting point and duration for a power boost.
• SLS channels have been added: dTLap_drElectricPowerFactorWithLapEnergyConstraint and dTLap_dPElectricPowerOffsetWithLapEnergyConstraint. These account for the energy cost of increasing power at a particular point around the circuit.