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Speed Limit Information Function (SLIF) Testing 

Efficient solution for validating EU regulated Speed Limit Information Function (SLIF) and Intelligent Speed Assist (ISA)

  • Precision Tools: Tailored to meet SLIF and ISA regulations 
  • Time-Saving: Quick setup and early stop feature minimise test distances and reduce overall testing time.
  • Seamless Integration: Compatible with video and CAN systems. 
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Test your SLIF system with VBOX Precision

VBOX Automotive offers a bespoke solution for validating Speed Limit Information Function (SLIF) and Intelligent Speed Assist (ISA) systems, now mandatory under EU regulations. This innovative solution combines the VBOX Touch, a bespoke free-to-download SLIF test app, and the SLIF Event Marker Box.

The SLIF App records distance data, road and light conditions, and OK/NOK inputs for speed sign accuracy, which engineers can manually log using the touch display or an additional Event Marker Box. The Event Marker Box also enables the driver to log specific events for detailed post-analysis.

Real-time data monitoring on the VBOX Touch screen includes measuring "True Positive_Distance", enabling early test completion if results stay within tolerance, and reducing driving requirements from 400 to 300 km. This approach saves time and resources, delivering actionable insights and improving testing efficiency. 

Under EU regulations, Intelligent Speed Assist became mandatory for all new vehicles from July 2024 and from 2026 will form part of the new Euro NCAP Safe Driving Vehicle Assistance Protocol. 

WHAT IS SLIF? 
Speed Limit Information Function (SLIF) is a vehicle system which identifies the current speed limit and displays it for the driver. The speed limit information is usually collected from a combination of information from the camera and the navigation system. 

WHAT IS ISA? 
Intelligent Speed Assist (ISA) systems are vehicle systems which consist of two elements; a SLIF for obtaining and displaying the speed limit and either a Speed Limit Warning Function (SLWF) or a Speed Control Function (SCF). A SLWF will warn the driver of exceeding the limit through appropriate driver feedback, and a SCF will automatically take measures to ensure that a defined speed is not exceeded.  

Key Features

Log Driving Metrics

Log and toggle road type and light conditions via the VBOX Touch App, ensuring complete data capture across a range of variables.

True Positive Distance (TP_D)

Automatically calculates TP_D, measuring the accuracy of vehicle display against road signage, ensuring precise compliance evaluations.

Early Stop Functionality

Reduce test driving distance if TP_D accuracy stays within +/-5% over the final 50 km, saving time and resources.

Enhanced Data and Video Integration

Synchronise with a VBOX HD2 camera to combine footage, TP_D data and event markers. CAN data can be captured for real-time display or for post processing.

SLIF Event Marker Box

Manual buttons to log key events and confirm matched speeds, providing actionable insights and simplifying result analysis.

CAN Output

CAN output from the VBOX Touch is available for seamless integration with data loggers or relevant equipment in a wider test setup. 

Testing Equipment

An ideal SLIF test setup consists of a VBOX Touch, an Event Marker Box and a VBOX HD2 Video unit, with the camera positioned facing the road and the dashboard with SLIF display.

VBOX Touch displays the Speed Limit Information Function (SLIF) Application which logs distance data, sign recognition inputs (OK/NOK) and TP_D (% of the Total Distance where display and road signs match).

The Event Marker Box is an alternative OK/NOK option and, in addition, triggers the events for review in post process.

GNSS and SLIF test data is synchronised to the VBOX HD2 video footage for easy post process in VBOX Test Suite. All testing channels are also output over CAN, for use in external loggers.

VBOX Touch displaying live results during a SLIF validation test. It shows that 106.19 km were driven on inter-urban roads under cloudy light conditions, with the SLIF display and road signs matching 96.68% of the time.
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The Event Marker Box logs events for post-processing review, such as in VBOX Test Suite. It also serves as an alternative option for OK/NOK logging.
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A VBOX HD2 Video unit with two HD cameras allows you to capture footage from both outside the vehicle (road view) and inside the vehicle (dashboard with SLIF display).
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