Mazda’s website quotes the system is designed to work within a ‘defined speed range’ but doesn’t quote figures. Would be good to get actual figures from Mazda on this then compare that with data from the car.
I’m sure I’ve read 12 mph somewhere - it’s an odd (peculiar) number that I wouldn’t have imagined, but that’s not to say that it’s correct of course! Probably the correct value will be a round number in kph (actually 12 mph is roughly 20 kph, which would make sense). Logically, there’s going to be some value of minimum activation speed, otherwise there would be a lot more instances of the system going off due to a simple parking nudge.
They’re accelerometer sensors
I daresay you’re correct as far as the sensors are concerned, but the system as a whole will be disabled up to a programmed speed (12 mph or not) to avoid spurious activation.
Ask the Mazda specialist what that speed is. And following that, what they think a car will do hitting a kerb at that speed. I think if I hit a kerb at 12mph, I would end up in someone’s front garden.
Do you know who makes it?
If the issue is to do with the sensor itself, it might be possible to find what other applications its used in, and then see if there are other similar reports in other marques. Far too few ND MX5s have been sold to build up a picture.
I don’t know if there can be some digging into the EU regulations to see if they have defined a standard for these systems, in terms of when they are supposed to activate, or whether a call to someone like Thatcham might yield some performance data on the device in use.
Its curious that when looking at the Japan owners manuals, after translation, the wording used uses the exact same weasel, evasive language to describe when the system doesn’t function.
Sensors are likely from Denso, but will have to check
Denso, in a previous post, showed off a pressure sensor, launched in 2013; when the bumper fascia deforms, it pushes on the bumper bar with the sensors fitted, deploying the bonnet. They claim its more reliable than other systems, with respect to false deployments.
I think even that statement from Denso is telling, acknowledging that there is an issue in the industry. Couple that to Mazda’s system; does the ND use basically a version of what was used on the short-run EU spec NC3, ie. an early iteration of this system.
Where is the sensor fitted? Anywhere near the front plate?
This subject crops up occasionally - the last time I think, was a couple of weeks ago, when I posted about being glad I didn’t have an active bonnet on my MX-5, because I hit a pheasant whilst passing a farm recently, and was so relieved that the only damage my car suffered was a dislodged fog light, which I was able to refit in five minutes.
At the time, I did a search on You Tube, and found that other car manufacturers were using a system that was re-settable within seconds, and didn’t damage the bonnet of the car at all. So why is the Mazda system so destructive ?
If Mazda used a non-destructive system on their cars, I’m sure there would not be so much fuss made when the things went off half-cocked !
Good find. So is the sensor literally located in the area of the “mouth”, about where an EU-spec elongated plate is mounted? How are these mounted these days. In years gone by, all the plate mounting hardware was fitted UK side, with varying degrees of skill.
Not all manufacturers are using non-destructive approaches. What might be an influence is the paltry number of ND MX5s made. When Mercedes brings out a new C-Class or E-Class, they know literally millions of these things will be sold, and often to users like cabbies. That pushes the development budget up. Barely 40,000 MX5s sell a year globally, and its declining.
Mazda on the other hand couldn’t afford to develop the ND MX5 on their own, they needed FCA. I’m not sure if these active bonnet technologies are sufficiently mature to allow development of multiple platform systems (eg. airbag steering wheels are all pretty much the same), or that the system has to be bespoke for that model (hence Mazda’s patent features a MX5, not a Mazda 3).The original MX5 was a bit of a parts bin car, and that kept the costs down. Is anything on the ND parts bin?
And ultimately, an Active Bonnet means an admission by a manufacturer that they cannot or will not incorporate EU pedestrian protection design into their cars (ie. cars with sufficient clearance between bonnet and engine don’t need this). Its an interim solution and maybe underdeveloped. And its moot because in 5 years time, or whenever the ND is replaced, there won’t be a petrol engine under the bonnet (or it might be a much smaller unit, if there is an Ibuki-style Hybrid system to boost power).
A superficial scan of manufacturer indicates the Japanese makers are preferring the destructive systems. This might be a result of having to comply with their own domestic standards.
is the explanation…
If you ask me this is a poorly designed system. There is a camera on the car that can recognise road signs and provide potential collision warnings. Why can’t this camera be used to determine that there MAY be a pedestrian in front of the vehicle and then and only then arm the active bonnet system. This could be done in milliseconds and the recognition system should err on the side of precaution i.e. if it sees anything that just may be a pedestrian at a reasonable distance then it should arm the system. It may prevent spurious actuations caused by pheasants, dogs and kerbs etc.
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A dog hitting the car isn’t spurious. Don’t hit a dog. It might have been a 3 year old child.
Birds and cats, the police don’t care. Dogs, they do. Hit livestock (sheep) and it further ratchets up.
I doubt Mazda will really care about redesigning the system and owners will have to put up with it, for the remaining lifetime of the ND. After that, the problem goes away (the NE won’t need this, if the NE goes ahead). Mazda needs to include a system, otherwise the car is off the market in Europe, Japan and Australia. Your effort should be in showing that the system is faulty, and that minimum speed threshold strikes me as key. No one I guess has bothered to contact DVSA.
I’m sure there are good reasons why dozens of engineers at Mazda decided that using an existing camera for this won’t work. But it comes down to cost, and clearly, the ND was released under developed, given the number of faults on it (customers are guinea pigs).
Because - “Not a lot of people know that”!
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Good points Saz but I think that a three year old child would be more likely to go under the car or hit the front of the bonnet/bumper not the mid/rear of the bonnet unlike an adult. If the system can warn you of obstructions it should be able to tell and arm the active bonnet if you are about to hit something other than a kerb, pheasant or errant wheel trim.
So a system ought to differentiate between a toddler being squished under your car, or an adult, because then at least you won’t have to deal with a bent bonnet on top of everything else.
A bigger dog might be like a 10 year old. How does that work? Over or under the car?
A camera I suppose might be defeated by a fly on the lens.
There is a conflation of two different incidents; flying objects on the road; I don’t think a system exists that can accurately model the size and mass of a moving object extremely quickly. I think drivers just have to live with that risk.
Hitting a kerb “at a normal speed” is another issue. If Mazda claims that the system is deactivated at below 12mph, then a car car hitting a kerb at more than 12mph will likely mount it, and pile into that stream of pedestrians. You probably want to minimise the injuries to pedestrians at that point.
If the car hit the kerb at a speed that most people would consider “normal”; 1-2 mph, then obviously there is a fault with the system. Unless Mazda designed this to be active at 1-2mph.
If Mazda did do this, then we’ll complain, and MX5 sales will tank. If the speed is higher than this, then its a warranty claim. It doesn’t matter why or how these cheap little g-meters go bad. But that speed needs to be obtained from Mazda.
In the event of a claim, isn’t there an engineer’s report?
Saz, I think that you are misconstruing what I am saying. What I was trying to say is that in most cases I don’t think that the Active Bonnet would help in the event of hitting a toddler. Unless I have misunderstood the system completely It is mainly the trailing edge of the bonnet that moves upwards to provide a buffer between the bonnet and the engine. I would not have thought that you would want the front edge to lift causing possible amputations. I am not comparing a toddler to a dog. As I said the software control algorithms would need to be very pessimistic and if there is any doubt at all, arm the system. If there is a fly or anything else obscuring the camera the syste should be programmed to arm the active bonnet. It should only disarm if there is absolutely nothing at all detected. Yes, maybe the system should and could also be capable of detecting a dog or toddler which I am sure it could do. If not, radar or ultrasonic sensors should be able to do this. I don’t believe it is beyond the abilities of Mazda’s engineers to come up with something better.
I agree in these cases that in the case of very minor kerb impact it is probably the speed parameters for actuation that are at fault (poor acceptance specification limits). It may also be a bad batch issue. However if Mazda are making money out of new bonnets, explosive actuators and hinges etc. I can’t see them rushing to provide a better system.
I’m not sure why the concept of the Mazda approach is so hard to grasp. The MX-5 is and has always been a flimsy, fun sports car. You can still confidently spot a MX-5 at 6 or 8 hundred yards or more waiting to pull out of a junction but not actually know which version it is until you get much closer. Mazda should be congratulated for not letting the car bloat like the BMW Mini or just about every other car that keeps evolving. To maintain that size, lightness and style to preserve that fun driving appeal then compromises need to be made. It would no doubt have been possible to design a system where the bonnet hinges were able to be reset as per Mercedes C Class but what compromises would have been required to do that? The spring devices are quite bulky, so that requires a styling change, space within the chassis design to accommodate them, the bonnet design to be different and probably made out of steel and extra reinforcing. There is far more space in a Merc and it weighs far more. Suddenly you have added 50Kg and resultant compromises on space etc result in a very different car and everyone moaning the famous 50/50 balance has gone and it looks ugly.
When the MK4 was released there were post on this forum saying “I’ll never buy one because…” the steering wheel does not move in every conceivable direction, the seats don’t go up and down and are not operated electrically, power hood etc.etc. If that is what is required then get a Z4 or SLC, the poverty spec ones start at £33K, but no one ever bought one of them for the fun of driving like people by a MX-5. The compromise for that fun of lightness and affordability is the car that is there.
As Saz said, the issue is knowing what the parameters that Mazda set for the bonnet to operate and if that has been met or not. It is the Merc ad that says 12mph, not Mazda. It may well be that the different and lower bonnet design on the MX-5 requires a lower activation speed and it is also very easy to underestimate the actual speed of travel at any particular point as anyone who has been caught speeding will know.
As for having a camera and software to determine a pedestrian strike, define a pedestrian! Do they have to be a standard colour? Wearing standard clothes? What happens in low light conditions? What happens if there a 6 people in a group? A hen party wearing TooToo’s? A stag party wearing dinosaur costumes? What about a pantomime horse? What about the person pushing the child in the buggy or the person on a bike?