RT-Range software release April 2011, List of changes

Software Releases

April 11, 2011

This has been a large RT-Range software release with a lot of new powerful features. Here is a list of the changes that we have made. The RT-Range manual has more details on how to use these features.

Target vehicles represented as polygons

The RT-Range now represents Target vehicles as polygons. The RT-Range computes the closest range from the hunter vehicle to a polygon representation of the target vehicle, automatically swapping points and even interpolating between polygon points. Up to 8 points can be used to represent the polygon. This new feature is especially useful for more advanced tests, like blind spot detection or collision detection at junctions. Read the full news article…

Hidden target vehicles

Evaluating radar or LIDAR performance for advanced driver assistance systems can be difficult when targets can be hidden behind each other. Using the new polygon targets feature of the RT-Range makes it much easier to analyse sensor data from hidden targets and benchmark performance. For pedestrian avoidance, it is essential to know how quickly the sensors can correctly identify the pedestrian. As a pedestrian steps out from behind a parked car, the RT-Range can precisely measure when the pedestrian became visible, or even the percentage of the pedestrian that is visible. Read more about this feature on the news page…

3D Range calculations

OxTS is introducing an advanced option to the RT-Range so that the range can be computed in 3D, rather than assuming a flat earth model. As the hunter vehicle pitches, sensors see differences in the forward range. This is more apparent when vehicles move to real-world situations where the road is not flat and uniform. Using the new 3D technique, the roll and pitch of the vehicles are taken into account when the forward and lateral ranges are computed. The roll and pitch are used to compute a new measurement plan (not horizontal). The target is projected in to this tilted measurement plan, mimicking the behaviour of radar and other ADAS sensors. Read the news webpage about this feature.

Lane Curvature in RT-Range

When testing vision systems for lane departure warning it is important to have a measure of the curvature of the lanes. Using new outputs from the RT-Range the curvature of each line is computed and output over the CAN bus. The output is available in real-time so that it can be captured and compared to real-time sensor data. Read the full news article here…

Lane Direction in RT-Range

Another key measurement for LDW systems is the angle of the vehicle within the lane. The new RT-Range software now computes the relative heading of the line markings compared to the heading of the vehicle. Read more here…

Target RT status on CAN bus

The RT Inertial+GPS navigation systems output many status messages on the CAN bus. These give information that can confirm that everything is working properly, increasing the confidence that the test results are valid. In the new version of the RT-Range software the status messages are transferred to the RT-Range and can be output on the CAN bus of the RT-Range. Read more on the corresponding news webpage…

Range velocity with polygons

The latest version of the RT-Range software now models target vehicles as polygons. However, if the target vehicle is perfectly lined up with the hunter vehicle, then the closest point is unstable, swapping from the left side to the right side quickly. This represents a large rate of change of lateral range, so a high lateral velocity. Therefore the RT-Range now computes the instantaneous velocity of the closest point and compares this to the velocity of the sensor point on the hunter vehicle.

Additional lane measurement outputs

The RT-Range now outputs the distance to all lane markings from three places in the vehicle. Previously only the range from one point (normally the centre of gravity) was output. The new CAN messages will output the distance from Point B and Point C (in the lane tracking module) to all of the lines in the map.

These measurements are useful when using maps for NHTSA’s LDW tests. When using the outputs that dynamically change throughout the test then it is possible for the outputs to stop before the end of the test because the vehicle’s point A has left the lane. By using the fixed measurements from points B and C to the lane markings the measurements are always output regardless of whether point A is in the lane or not.

Range accuracy outputs

As the distance between two test vehicles increases, the lateral range accuracy (or uncertainty) increases because of the heading error. The RT systems include an output which tells the RT-Range how accurate the heading is. This can now be used to estimate the accuracy of the forward and lateral range.

RT-Range configuration data on CAN bus

Often the person analysing the data from sensors and from the RT-Range was not present during the test. To help, the RT-Range now outputs some critical information about the configuration.

In the range module the following configuration parameters are now output on the CAN bus:

  • Range Offset
  • Fixed Point Latitude, Longitude, Altitude
  • Sensor Lever Arm (from the RT to the sensor point on the hunter)
  • Bulls-eye Lever Arm (from the RT to the bulls-eye on the target)
  • Polygon number (when using a polygon for the target this is a user entered number to identify the polygon and therefore the vehicle).

In the lane tracking module the following configuration parameters are now output on the CAN bus:

  • Lane Point A Lever Arm
  • Lane Point B Lever Arm
  • Lane Point C Lever Arm

Knowing the configuration information often helps the person performing the analysis to understand what vehicles and tests the data refers to.

RT-Range Vehicle Length and Width on CAN bus

As well as adding some configuration information to the CAN bus we have added some user defined quantities: vehicle length and vehicle width. The RT-Range passes these values through the software and puts them on the CAN bus. This information can also be used to identify what data the test refers to in the future.

Time to collision (TTC) with acceleration

The original time to collision calculation in the RT-Range used range and range velocity to compute the time to collision or impact. However, for some of the NHTSA tests the acceleration also needs to be included in the time to collision calculation.

The RT-Range now outputs both the original time to collision calculation and a new version, time to collision with acceleration. This new output should make it clear what the RT-Range is computing and provide backward compatibility for customers who do not need the version with acceleration in it.

DeltaX and DeltaY local co-ordinate outputs

For the NHTSA FCW (forward collision warning) test it can be easier to set up local co-ordinates with the x-axis along a straight section of track. The new DeltaX and DeltaY measurements become the effective range between the vehicles in the road co-ordinates, rather than in the hunter vehicle’s co-ordinates.

The advantage of this calculation scheme is that it removes “noise” in the lateral range when the hunter is a long way from the target. This noise is caused by small variations in the heading of the hunter vehicle as the driver tries to keep the hunter vehicle driving in the correct direction. By computing the values in road co-ordinates, rather than hunter vehicle co-ordinates, the heading angle of the hunter vehicle is not included in the calculation and minor steering adjustments to the hunter do not affect the results.

Status Messages from Target Vehicles on Hunter CAN bus

Previous versions of the RT-Range only output the navigation CAN messages for the target vehicles. These messages included measurements like latitude, roll, heading, acceleration, etc. Status information like “number of satellites” was not available in the hunter vehicle.

Now we have added the ability to repeat most of the status messages of the target RTs on the RT-Range CAN bus. This will give access to virtually every possible output in the RT-Range. Since the CAN bus is not fast enough to transmit all of the data you will need to select which messages you want to transmit and which ones you want to disable.

Filtered target and hunter acceleration

It is possible to set a filter so that acceleration is filtered before it is used by the processing algorithms. The filters can be set independently for each target, i.e. you can have different hunter filters for each target.

The hunter acceleration filter can be set so that the acceleration for NHTSAs FCW tests can have filtered acceleration in the calculations. The target acceleration filter is useful when using the ABD robot where there can be undesirable noise when the hunter is trying to follow the path of the target.

Heartbeat lane message

The heartbeat messages are used to check that the CAN bus is working before any of the RTs are initialised. Without these messages the RT-Range will not output any CAN messages unless the RTs connected to the RT-Range are initialised and connected properly.

The original heartbeat messages were output as part of the range module, which meant that they were not output unless some targets were configured. A new lane tracking heartbeat message will be output when a map is loaded into the RT-Range so that a heartbeat message is available when lane tracking and when the hunter RT is not initialised.

Improved screen drawing in Line Survey and Map Wizards

The number of points in the line survey and map wizards has been increased so that more than 10,000 points can be manipulated. The restriction in the past was based on the screen drawing method that was used. Now the screen will update much faster, so it is much easier to have maps with large numbers of points.

Cone Placement from Line Files

Don’t forget that Enginuity (from the RT software) now has a cone placement function so that cones can easily be laid out on the ground. You can use the RT-Range Line Survey Wizard to measure the position of cones on the ground. Then you can replace these cones at a later date. You can move the cones to another location and replace them accurately on the ground. The positions can be checked in Google Earth before the cones are laid.

Start and Stop Lines in Save to RCOM

It is now possible to configure a start line and a stop line in the “Save to RCOM” window of the Real-time Display. Logging can start automatically when the vehicle crosses the start line and then stop after the vehicle crosses the stop line. The position of the hunter or any of the targets can be used – the vehicle being used in the Real-time Display will be used.

RT-View improved RCOM loading

RT-View has been updated to include the new measurements from the RT-Range. You can load saved RCOM files and see the range data and the information from the RTs.

RT-ViewDx

A beta version of RT-View is available. This uses a new data storage object, one that is capable of loading far more data types. This beta version has a different name so that it can be loaded at the same time as RT-View. It includes a lot of additional RT measurements, including many accuracy fields and status fields. Eventually RT-View will incorporate the RT-ViewDx engine when all of the features are added in.

RT-View unit management

The latest version of RT-View includes better management of the units. We are adding the concept of a “default” unit. When the “default” unit is set then the graphs and tables based on the default will change too. New measurements will be added in the default units.

If you have any questions about the latest RT-Range software features, please do not hesitate to contact our experienced Support Team at OxTS: Contact us