There is much jaw-jaw around ADAS and Autonomous vehicles at the moment, and rightly so, but it may have left you feeling a little jaded, hearing about the latest and greatest tool companies’ ADAS calibration equipment. However, the automation of the act of driving a vehicle is big, it’s here, and it will affect you, your business and the way you work.
First off, let’s do a bit of jargon busting. Autonomy means a state of self-governing, therefore an autonomous vehicle has the ability to self-govern; that is, it will have the capability to carry out a range of operations without any direct input from the driver. ADAS, or Advanced Driver Assistance Systems, is the banner under which the different elements or sub-systems of the autonomous vehicle are referred to. Common ADAS* (we can’t really say ADAS systems, because the ‘systems’ bit has already been referenced) include:
Adaptive Cruise Control: Where the host vehicle maintains a commanded speed and, if relevant, a defined distance from the vehicle in front.
Active Lane Assist: Where the host vehicle will monitor the vehicle’s position in a defined lane and move the steering wheel to maintain that position.
Adaptive Front Lighting: Where the host vehicle directs the headlight beam in the direction of steerage.
Autonomous Emergency Braking: Where the host vehicle detects the proximity of surrounding vehicles and automatically applies the brakes to prevent or reduce the effect of a collision.
Blind Spot Monitoring: Where the host vehicle uses sensors to detect vehicles to its side (blind spot). In conjunction with Steering Assistance Systems, the host vehicle may deliver corrective steering torque to maintain the vehicle’s position to prevent a collision.
Pedestrian Assist: Where the host vehicle uses sensors to detect pedestrians in the path of the vehicle and automatically brakes to avoid a collision.
Traffic Sign Recognition: Where the road signs (such as speed limits) are recognised and an appropriate indication or warning is given to the driver.
*different vehicle manufacturers may use slightly different terminology. We have described the systems in generic terms.
There are variations in the systems which range from warning the driver if the defined conditions aren’t being met, to active intervention to ensure that the defined conditions are met, and/or collisions are prevented, or their impact is reduced.
In order to function, these systems make use of several key components and sub-systems; some of these may be new to us, such as Radar and LiDAR, others are adapted mechanical systems with which we will be familiar, such as electronic power steering, and anti-lock braking. Blending these ADAS elements leads us towards autonomous vehicles.
Levels of autonomy
There are six defined levels of autonomous vehicles, as set out by the Society of Automotive Engineers. Level 0 – The base level of no automation. Level 1 – Driver Assistance, where the vehicle can assist with tasks such as steering, braking and acceleration. These functions are enabled by the driver and are not automatically applied by the vehicle. Level 2 – Partial Automation. Two or more automated functions work together to relieve the driver of control. Level 3 – Conditional Automation. This is defined as the execution of steering and acceleration/deceleration and the monitoring of the driving environment. Level 4 – High Automation. At this level, the vehicle doesn’t require a driver. The vehicle is capable of all aspects of the control of the vehicle, under certain conditions, and the driver can intervene. Level 5 – Full Automation. This is where the vehicle can perform all aspects of driving under all conditions.
So how will ADAS affect technicians and independent workshops? Firstly, diagnosing and rectifying system malfunctions. This will bring new components into the technical realm for test and measurement. Diagnosing on- board camera and radar function, for example. Secondly, performing calibration on the systems after other mechanical repairs. If, for instance, the front panel of the vehicle is removed during a timing belt renewal (and the radar mounting is disturbed), the system requires recalibrating. The same is true for any work which affects the steering geometry (track rod ends, ball joints, suspension bush/arm replacement) or the ride height of the vehicle (new shock absorbers, upgrading alloy wheels). The vehicle may have one or both forward and rear facing radars as well as a forward-facing camera.
There are obvious safety implications of using a vehicle when the base calibration is incorrect. The margins for error are very small. The range of these sensing devices can be up to 300 meters, where a 1 degree sensor alignment error leads to a 5.2 meter focus error (almost the width of three cars) at this distance. This could cause the vehicle to be unable to detect an object until it is much closer, causing a delay in the moment of intervention (Time To Collision), leading to a potential collision.
Calibration rigs are widely available and are usually accompanied by a suitable scan tool. The scan tool initiates the system’s calibration process and the calibration rig contains the reference targets. Most system calibrations cover both the radar sensor and the camera unit. Validation of the vehicle’s wheel alignment and the mechanical base alignment of the radar(s) and camera sensors is critical prior to any calibration events. Technicians who carry out ADAS calibrations must ensure that the calibration environmental conditions match the vehicle manufacturer’s requirements. They should also be able to demonstrate competence (through an accredited ADAS qualification) and keep appropriate calibration records (evidence of geometry and calibration data). A vehicle with a non or incorrectly calibrated system presents a significant liability for the technician, the repair business, other road users and the driver.
With the European Union mandating that all vehicles be equipped with autonomous emergency-braking systems, lane keeping, forward-collision warning systems and speed assistance in the next couple of years, the opportunity for workshops is growing rapidly. As always, the key to doing it correctly is learning about it. Technical Topics run accredited ADAS Calibration Training on their Accredited Diagnostic Technician and Master Technician Programmes. See www. techtopics.co.uk/training for details.