I always enjoy this segment of writing as I get to share some of my learnings with you – the progressive automotive repairer… writes IAME CEO Peter Blanshard
Over the last few editions, I have been discussing control techniques for new advanced intelligent vehicles, or should we now start to call it transportation, as it’s more than just a car or vehicle. I would like to discuss firstly predictive cruise control. This feature has been used by manufacturers such as Mercedes and Volkswagen, but only in limited supply.
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Our original cruise control was simply to keep ‘a speed’ and never used brakes to assist in retarding the system on major slopes. In later years cruise control started to adapt to this and we then crated adaptive cruise control, mainly for use on motor ways where a motor vehicle sensor would identify a vehicle in front and retard your speed so that it would fall in behind. You had to move out to a clear lane before your vehicle would accelerate back up to the desired set speed.
At your own pace
Today, with predictive cruise control, it uses advanced GPS settings and radar to identify your vehicle position and speed versus the approaching driving conditions. The systems will operate one to two kilometers in advance and will retard your speed when approaching a roundabout or a heavy swept corner on the GPS. It will match your driving speed to the advisory speeds of the potential hazard in front.
Naturally, as with adaptive cruise control, once you have been travelling through that heavy bend or roundabout, the vehicle will accelerate back to your pre-set speed. This type of sensory control system is obviously a part of a forerunner or autonomous drive but we as technicians will be introduced to these types of systems prior to the full-blown autonomous drive vehicle. This is why I advocate for constant learning as an automotive technician in 2023.
Plug ‘n’ play
Continuing the subject of cruise control, we now must turn our attention to systems that operate in EVs.
Electric Vehicles on a sloping road to travel at a constant speed can be something which adversely draws high power from our batteries, and we are developing a system called eco cruise control for electric vehicles. The best way to describe this is to copy it from the academic editor Peng Hang who writes for Hindawi on research articles. Here is an abstract which probably best describes the fundamentals of eco cruise control in EVs:
“The unreasonable actuation of electric vehicle’s motor drive system usually results in a lot of unwanted energy consumption on a sloped road. This paper proposes an eco-cruise control (ECC) scheme based on the driving condition estimation to decrease electric vehicle’s energy consumption in the constant-speed cruise control mode. The eco-cruise control scheme is realised by reducing the unreasonable actuation of the motor drive system.
“The vehicle’s total mass and pitch angle are estimated in real time by using an improved basevector- based cross iteration estimator (BVCIE). Based on the estimated results, the required torque is predicted. Combining the speed deviation between the desired speed and the real speed, and the torque deviation between the required torque and the real torque, a three-power nonlinear controller of the ECC scheme is designed.
“The ECC scheme is validated on a slope road with different cruise speeds on a cosimulation platform, and the results indicate that the proposed strategy enjoys a better speed maintenance ability and energy efficiency compared with the benchmarked cruise control.”
Wheel ‘n’ deal
Again, in previous articles, I have written about run flat tyres and indeed about advanced wear that can occur when replacing run-flats with conventional radials on EVs. The next part of this problem is that consumers are very used to purchasing only two tyres at once and because of the handling difference between a hard compound run-flat tyre and the standard conventional radial it is not recommended that you only swap two tyres at a time. The EVs with two run-flats and two conventional radials can potentially have handling characteristics change to the point where your electronic stability program struggles to understand what is occurring.
Our onboard systems/sensors are designed to work with certain parameters and when you mix and match run-flats with standard radials, this handling characteristic of the vehicle in most cases goes out the window. If a consumer wishes to convert away from run-flats, it is recommended nowadays that you sell them four radial tyres or replace the four run-flats. Do not mix the two types of tyres.
In life, you often get what you pay for, and we have noticed some lithium battery packs entering our market originally designed for the four-wheel drive or recreational vehicle market but now has been picked up as an additional high-power source for sub-woofers and stereo componentry in certain vehicles. The concern does not really lie with the construction of the twin-lithium based batteries but more so with the battery maintenance pack. This has been evident in the mobility scooter area where we have had thermal events with the batteries on mobility scooter/chairs where the battery maintenance or charging packs have failed and a battery has overheated to the point of ignition and major damage occurs.
These twin-lithium battery packs which is supplied for automotive use were originally designed for caravan application. Here, they provide a current for fridges and other onboard electrical equipment within the caravan during hours when there has been no sunlight or solar or the vehicles is not physically driving or running for the normal charging system to operate. These twin-battery packs serve the purpose well, however the adaptors or systems that charge these batteries are a point of concern and since we now have a lot of young kids bolting these packs to the floor or their car or inside the boot if a thermal event was to occur the result would be completing devastating. Please be aware and only assist your customers in purchasing quality products not cheap internet sourced products.
Back to it
Your IAME has always supported speed from the streets, and we enjoy working with the team that runs the drag racing series known as Jamoboree. Last weekend the Queensland drag racing season opened with the Willowbank Jamboree and
I am pleased to announce records crowds and a brilliant showcase of drag racing, we unfortunately did not break any Australian or world records but the number of competitors that stared the opening round of the season with personal best results was amazing. There has been some quality off-season work carried out on these vehicles and personal bests were achieved nearly every second run. We look forward to the next Jamboree event at The Bend in South Australia.