SIDESLIP ANGLEEstimator

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Side-Slip Angle (beta) Estimator(SSE 2.0)Our Side-Slip angle Estimator (SSE 2.0) is a software algorithm ready to be integrated in any ECU.

This algorithm runs in Real-Time on a fraction of the resources already available on modern ECUs (15% CPU occupation on Infineon TC1767) and uses exclusively the data already available on the vehicle CANBus.

It is insensitive to different tire sizes, tire conditions, environmental (grip) conditions.

It is certifiable as ISO 26262.

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How does it workThis algorithm is based on a new mathematical methodology generally known as Deep Learning.

This approach is extremely effective in finding meaningful and complex correlations in data. We use it to find such correlations between the signals available on the CANBus of every vehicle and the Sideslip Angle.

Once the model is calculated from the experimental data, a light version of the model is translated in highly efficient embedded C code ready to be installed on the vehicle ECU.

Features•No Additional Sensors: works with CANBus data @ 50Hz or 100Hz

•Robust (insensitive) to Tire Wear and Temperature

•Works in any handling and road conditions

•Available for 2WD and 4WD and 4 wheel steering vehicles

•Wheel Speed

•Front Steer Angle (and rear steer angle when available)

•Ax; Ay; Yaw Rate

Technical Data•ZERO response Lag

•Maximum estimation Error on Wet / Dry conditions: 0.4° RMSE

•Maximum estimation Error on Snow / Ice: 1.1° RMSE

•Vehicle Speed: from 10 to 300 km/h

The sideslip angle estimator uses only the informations already available on the vehicle’s CANBus.

This is important because it means that it does not require any additional hardware: this is just a pure software implementation.

Our algorithm has been integrated in the controls of thousands of production cars ranging from two to four wheel drive and from two to four wheel steering

vehicles.You can find a full description of the SideSlip Angle Estimator algorithm in a

separate presentation.

•2 wheel drive (rear)

•4 wheel steering

•High Performance GT vehicle

SSE 2.0 - sample output - Frequency Sweep

Frequency Sweep - 2 wheel drive / 4 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

This is the real-time estimation of our algorithm compared with the raw data measured with a Correvit Datron system on a typical frequency sweep maneuver

The Correvit Datron signal is shown in blue and shows that typical instrument’s noise, the sideslip angle estimation from the SSE 2.0 is shown in red.

Frequency Sweep - 2 wheel drive / 4 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

Zooming on the frequency sweep details we see that there is no lag in the signal and the estimator

is always in phase with the reference signal.

SSE 2.0 - sample output - High to Low Beta (sideslip) angles •2 wheel drive (rear)

•2 wheel steering (front)

•High Performance GT vehicle

High, Medium, Low Beta - 2 wheel drive / 2 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

Here we check the performance of the estimator at different sideslip angles: High, Medium and Low Beta.

High Beta - 2 wheel drive / 2 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

At high beta the system shows an excellent performance. It’s important to notice that it doesn’t

show any lag in the response and that the signal dynamics is correctly estimated.

Medium Beta - 2 wheel drive / 2 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

The same performance is maintained at medium sideslip angles

Medium Beta - 2 wheel drive / 2 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

At low sideslip angles the estimator act as a filter removing much of the noise affecting the physical sensor.

SSE 2.0 - sample output - High Frequency Maneuvering•2 wheel drive (rear)

•4 wheel steering

•High Performance GT vehicle

High Frequency Manoeuvre - 2 wheel drive / 4 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

The quality of the response and the absence of lag is evident in high

dynamics maneuvers.

High Frequency Manoeuvre - 2 wheel drive / 4 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

This is important because our algorithms are employed both for performance control systems and as a support for

safety systems.A safety manoeuvre, like an obstacle avoidance, involves a high dynamics

driver’s action: in those cases it’s vitally important for the estimator to have a fast

response with zero lag

SSE 2.0 - sample output - Icing and Snow + Banked Conditions•4 wheel drive

•4 wheel steering

•High Performance GT vehicle

Ice & Snow on banked ring - 4 wheel drive / 4 wheel steering GT carCorrevit Datron - SSE comparison on Validation Dataset

Last but not least is the behavior in snow and icy conditions.Our algorithm can be enhanced to work in very low grip conditions

(typically snow and ice).Here we see the system tested on the data acquired from a four wheel drive,

four wheel steering vehicle on a banked testing track in Sweden.The results are very good in particular at the higher sideslip angles that in this

case are more than 50 degrees, moreover this test shows the strong insensitivity to the road bank that in this particular test was not negligible.

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Addfor s.r.l.www.add-for.com

P.zza Solferino 7Torino 10121 (TO) - Italy