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Yamaha YZF R1 mode operation
2

Yamaha YZF R1 mode operation

Yamaha YZF R1 mode operation

(OP)
The Yamaha YZF R1 and other motorcycles have introduced engine power profile modes. How is this accomplished and what would be required to retrofit the same functionality to other motorcycles?

RE: Yamaha YZF R1 mode operation

That is a fully drive-by-wire engine in that bike. What you do with the throttle (and with that mode selection switch) all goes into the computer (ECU) and the computer then operates various devices (throttle position servo motor, ignition coils, fuel injectors, etc) that make the engine function.

The mode selection switch is simply a switch with several outputs that go into the ECU.

Inside that computer are many "maps" that take various inputs and produce various outputs depending on what the input conditions are. One set of those "maps" is the one that takes RPM and rider-requested engine output (from your right wrist) and outputs what the target position is for the throttle actuator servo motor on the throttle bodies. The mode selection is very simple: selecting a different mode selects a different map to use. One of them (let's say, the "full power" map) may take a rider-requested 50% throttle position and command (let's say) a 50% position for the actual throttles on the engine. Another one (let's say, the "rain" map) may take that same rider-requested 50% throttle position and command (let's say) 20% position for the actual throttles on the engine.

If you have an engine that uses fully drive-by-wire controls, this is dead simple to do, even when it is as pointless as the "Sport" mode push-button on my underpowered Fiat.

If, on the other hand, your engine has the old style mechanically operated throttle bodies, it is not possible to do this!

RE: Yamaha YZF R1 mode operation

(OP)
Noted. When you say "mechanically operated" throttle, you mean a physical connection like a cable controlling the inflow? Didn't all superbikes go wireless after 1996? How do you make sure you have wireless throttle control?

RE: Yamaha YZF R1 mode operation

Yes, "mechanically operated throttle" means a physical connection with a cable. And no, full drive-by-wire has not showed up until recently. The 1996 threshold for cars going all drive-by-wire came about because of OBDII requirements, but motorcycles aren't required to have that (yet - not even today) so it doesn't apply.

Motorcycles went through an intermediate phase in which each throttle body had two throttles in it - the mechanical rider-operated one, and a secondary servo-operated one. My 2004 ZX10R is like this. Theoretically you can do the ride-mode arrangement with that design, by using the secondary throttle to do it (those engines still have an ECU-controlled mapped connection between rider-operated throttle and how much to open the servo-operated throttle), but the multiple ride mode deal did not become common until full drive-by-wire did.

You find out if you have drive-by-wire by taking a physical look at your throttle bodies to see how they work.

RE: Yamaha YZF R1 mode operation

(OP)
@BrianPetersen
It's guys like you that make visiting this site worthwhile. I was looking at a used YFZ circa 2002 and was wondering if that Yammy's power output could be mapped like the current ones.

RE: Yamaha YZF R1 mode operation

Nope, those have throttles operated by a cable.

RE: Yamaha YZF R1 mode operation

(OP)
@BrianPetersen
Right again, it looks like the electronic throttle was introduced in the 2007 model of that bike. All my questions were answered on this topic, thanks.

RE: Yamaha YZF R1 mode operation

A further note: Brian has described the basic funtionality pretty well, but in the actual application for Yamaha (and I have to assume everyone else...) the interaction is more complicated than just scaling the throttle input. The yamaha actually damps throttle movement, at a rate different for each map and different in certain parts of each map.

So the least-sensitive throttle mode requires large throttle inputs to get large throttle openings, but it also damps small oscillations or rapid changes in throttle input, and creates very smooth true throttle position plots.

This behavior took a lot of calibration on Yamaha's part, and would be really difficult to effectively do yourself.

RE: Yamaha YZF R1 mode operation

And to add, all the throttles are mechanically operated either drive by wire or throttle by driver.
The difference is the drive by wire is operated by computer and uses a servo to move the throttle, and the throttle by driver is of course by driver.
The advantage of drive by wire is the computer calculates proper operation parameters from the various sensors and its program, the same that electronic fuel control (efi etc.) systems do, only now with throttle control added to the equation.

RE: Yamaha YZF R1 mode operation

(OP)
@jgKRI @enginesrus
Thanks for the additional details. Am I correct to assume the "wireless throttle" acts like a motorized pot where the step clicks are calibrated to match the engine response profile or is it resistor/gate current based? This would explain how the same motor can be made to act like several different ones. As I understand it, there is a 3rd party that has a library of power delivery profiles that work with their own system (Power Commander?) Since we've shifted to the topic of engines, can a Yamaha later version FZ-1 engine be mounted to an earlier version R1 frame?

RE: Yamaha YZF R1 mode operation

I can't make head nor tail of your last post. The throttle on the throttle bodies is operated by a stepper motor and there is a feedback sensor on the throttle shaft. Rider requested throttle position is an input to the ECU along with the map selection and many other things. The ECU does calculations which arrive at a target position for the actual throttles on the engine based on a bazillion inputs and the various maps inside the ECU that translate those inputs into a target value. It then operates the stepper motor so as to achieve that target position.

If you want to change the way the bike responds to the throttle, you select a different map inside the ECU.

If you don't like any of the stock throttle position maps inside the ECU, through aftermarket channels you can have the ECU reflashed.

By the way, that bike is really restricted in stock form, and it doesn't matter which map you select, they're all restricted. Rider-requested 100% throttle only commands 100% actual throttle position in a fairly narrow RPM range. At higher revs, towards redline, it starts shutting the throttles. I smell lawyers.

FZ1 engines are related to previous-generation R1 engines but aren't exactly the same. The 2009+ R1 uses the crossplane crank and has an uneven firing order. I don't think the FZ1 ever got that engine. I don't know why you would want to put an FZ1 engine into an R1 even if it's the version that uses the same engine generation (not the same model year). The cylinder head is different; I'm not 100% sure but I think the FZ1 doesn't even use downdraft ports, which means the engine as a whole won't even fit in the chassis because the intake system would be at the wrong angle. You can probably do some mixing and matching but I don't see the point. R1 engines aren't rare.

RE: Yamaha YZF R1 mode operation

(OP)

Quote (BrianPetersen)

The 2009+ R1 uses the crossplane crank and has an uneven firing order. I don't think the FZ1 ever got that engine.
Yes, I know. The later R1 motor also has the more conventional 16V arrangement. Note the engine response of the FZ-1 described in the following link: http://www.motorcycle-usa.com/2007/10/article/2007-yamaha-fz1-comparison/. It uses the same, barely manageable 20 valve motor of the 2002/03 R1. I suspect this change in character of said motor is achieved by an ECU controlled throttle on the FZ-1 and that was the foundation for my question about the swap. A motorized pot is a programmable, electrical proportion control that uses a resistor or transistor/FET to effect the electrical change. See "motorized pot volume control". If the throttle maps are not controlled by a motorized pot, then what creates the change in input? I hope that cleared up the confusion from my post.

RE: Yamaha YZF R1 mode operation

Quote (gmaslin)

A motorized pot is a programmable, electrical proportion control that uses a resistor or transistor/FET to effect the electrical change. See "motorized pot volume control". If the throttle maps are not controlled by a motorized pot, then what creates the change in input? I hope that cleared up the confusion from my post.

The system you're attempting to understand is much more complicated than that. It isn't a simple arrangement of analog electrical components (which a motorized pot is)- it is a fully digital control system with many levels of inputs and feedback loops.

The throttle mounted on the handlebar and operated by the rider has a position sensor. The reading from that sensor is an input into the ECU, usually denoted as requested throttle position.

The ECU takes that input, puts the value into an algorithm with many other variables from other parts of the system (which throttle mode is selected, front and rear wheel speeds, engine RPM, selected gear, brake pressure, lean angle, current commanded throttle position, etc etc etc) and calculates the commanded throttle position, which moves the physical throttle bodies to some opening percentage.

There are no simple analog components anywhere scaling voltages or currents to achieve throttle control- there's just a rotary position sensor (on the handle bar), a computer doing a lot of calculation (the ECU), and a stepper motor (on the throttle shaft). The physical configuration of the system would be very easy to replicate- you could buy a shaft position sensor and a stepper motor and make them talk to each other very easily.

The difficulty in replicating this system is due to what happens inside the black box- unless you know all the variables the ECU is using, how they affect commanded vs. requested throttle position globally, and how that global value is affected by the throttle mode mapping, you can't replicate the behavior.

RE: Yamaha YZF R1 mode operation

(OP)
@jgKRI
If I understand you, the throttle control is totally from the PLA interface on the ECU. This makes sense from the perspective of having a centralized input processor. What is required on the engine for it to be completely controlled by an ECU? Is it more than a compatible set of sensors with programmable injectors?

RE: Yamaha YZF R1 mode operation

An ECU is a computer in the sense that it computes, but it's not a Computer running windows. There is no PLA interface.

The hardware in the ECU and the devices it drives are specially designed, and the method of communication between them does not follow some global standard.

What is required on an engine for it to be completely controlled by an ECU?

Spark, air, fuel.

-enough injector drivers in the ECU to drive enough injectors to run the engine
-crank position sensor to tell the ECU where the engine is in its cycle

-enough ignition coils to fire all the plugs, or an interface to an external ignition voltage supply (MSD or whatever)
-cam position sensor to separate compression and exhaust TDC, unless the engine is to be run wasted spark

-Throttle control via whatever means is appropriate

Making an engine start and run with ECU control is relatively easy- we've been doing it in some form or another for going on 50 years now.

Making an engine meet emissions, run well, produce good useable power where it needs to produce good useable power, survive abuse, etc etc etc is more difficult.

RE: Yamaha YZF R1 mode operation

(OP)
@jgKRI
How are you so certain a simple PLA (programmable Logic Array) couldn't map a throttle to a known power curve? The ECU may have more sophisticated functions that require a more complex language structure but I don't see the throttle control as one of these. All it is doing, or should be doing, is to calibrate the circumference turned to the power output. PLA should be more than adequate for this task. Also, if the ECU is not directly controlling the servos that make the mechanical changes, it must be electronically controlling the devices directly. This can be much simpler than we are imagining it. The control of the spark and fuel intake is all you need to control the engine. The air is a derivative function as I see it and so is the exhaust in a normally aspirated engine. Remember, I'm not trying to rewrite an entire map of ECU functions, just a calibration of a throttle to engine power which has a predictable output curve.

RE: Yamaha YZF R1 mode operation

"Could it", perhaps.

"Is it a good idea", probably not.

One of the main reasons that full drive-by-wire took so long to implement, and why all the Japanese manufacturers went through a halfway-house step first (I don't know what the European manufacturers did), is safety. A drive-by-wire system has to be sufficiently fault tolerant that it does not cause safety-related problems on its own. The halfway-house steps (in which there is a rider-operated-mechanically throttle in addition to the drive-by-wire throttle) mean the ECU is only capable of reducing engine power, it can never command more power output from the engine than the rider is requesting. It's one thing for an error to cause a 100 hp engine in a 2500 lb car to go "oops", quite another if a 160 hp engine in a 400 lb bike goes "oops".

The systems had to be developed sufficiently to have a level of confidence in the reliability of these systems.

The other thing that makes it more complicated than a simple one for one mapping of rider-requested t0 servo-commanded is that there are a whole bunch more functions integrated into the system. Idle speed regulation. Cold start fast idle. Engine braking management. Traction control. Emission control (the rate of opening and shutting the throttle is a factor). Managing driveability. In some cases, cruise control.

RE: Yamaha YZF R1 mode operation

As usual, Brian is right on target.

There's a LOT more calibration in a drive-by-wire system than just making the throttle opening curve match the driver in put in a logical way.

Quote (gmaslin)

How are you so certain a simple PLA (programmable Logic Array) couldn't map a throttle to a known power curve?

I'm not certain that it couldn't be done this way- but for reasons named by Brian above and many other reasons, it isn't done this way.

Quote (gmaslin)

The ECU may have more sophisticated functions that require a more complex language structure but I don't see the throttle control as one of these.

See Brian's post above. Implementation of full drive-by-wire doesn't just mean scaling the throttle grip to the stepper motor- it means complete control over every throttle function, which was previously handled mechanically, by the control system. These bikes have zero mechanical throttle adjustments. Everything is done electronically. It's complicated to get right.


Quote (gmaslin)

All it is doing, or should be doing, is to calibrate the circumference turned to the power output.

Again.. not the case. It is doing much more than that.

PLA should be more than adequate for this task. Also, if the ECU is not directly controlling the servos that make the mechanical changes, it must be electronically controlling the devices directly. This can be much simpler than we are imagining it.

The ECU, as far as I know, provides both power and digital control of the stepper motor on a late model R1. As far as wiring and layouts are concerned, the system could not be simpler; but the mechanical arrangement of parts is simple. The development of control algorithms is the complicated part.

Quote (gmaslin)

The control of the spark and fuel intake is all you need to control the engine. The air is a derivative function as I see it and so is the exhaust in a normally aspirated engine. Remember, I'm not trying to rewrite an entire map of ECU functions, just a calibration of a throttle to engine power which has a predictable output curve.

I don't know what you mean by 'derivative function'- but for any conventional gasoline fueled four stroke engine, air intake (more accurately, intake manifold pressure) must be regulated. Remove the throttle bodies from your bike and start the engine- I can guarantee you won't like what happens.

You could very easily implement your own homebrew version of drive by wire throttle- all you would need is a position sensor on the throttle grip and a stepper motor on the throttle shaft, and a very basic device to cause one to drive the other.

I would not advocate doing this- first of all, the stock cable is reliable and tested. A homebrew electronic solution would be highly unsafe.

Brian is 100% right about that fact that compared to an average car, throttle faults on a high powered motorcycle are much more dangerous.

RE: Yamaha YZF R1 mode operation

(OP)
@MacGyverS2000
Welcome and thanks for the scare :/

@jgKRI
The throttle only has one function as I understand it and that is to increase/decrease the fuel flow into the engine. All the other functions you describe are already being handled by the ECU. I think you have been overly impressed with this technology. It's logic not magic.

@BrianPetersen
Yes, I concur that there is a much greater consequence of fault with a power bike but this can be managed by redundantly defaulting a closed throttle (ie: no fuel flow) in several forks of the program. It may need to read the state of the ECU to accomplish this so there is the challenge.

RE: Yamaha YZF R1 mode operation

Be careful ... "No single component failure shall result in the loss of the safety function" ... you have an analog input sensor, an analog-to-digital input to the ECU, the microprocessor hardware, the microprocessor software, digital outputs to the stepper motor, another analog sensor for the throttle feedback position, and another analog-to-digital input. It's not enough to just have your program command zero throttle position if it detects something wrong. And that's assuming that it has enough smarts to be ABLE to detect something wrong. A single-channel sensor and single digital-to-analog conversion, on its own, doesn't have enough information available to distinguish between a normal sensor reading, an open ground wire, a crossed circuit in the wiring, etc.

I'm used to automation equipment where, if a safety-related device or system has a fault, you just shut everything down every way you can to stop the equipment.

In an aircraft ... you can't do that. Systems that have to STAY WORKING in the presence of a component failure are far more difficult to get right than systems that can just (in effect) pound on e-stops and slam valves shut in order to achieve a "safe" condition.

A motor vehicle is somewhere in between.

The reference to Toyota's issues not too many years ago is entirely appropriate here.

RE: Yamaha YZF R1 mode operation

Vehicles, in general, do not have redundancy built in. For instance, if your steering column snaps in two you don't have many options. In contrast for brakes you do have a bit of redundancy, so long as the failure occurs after the main cylinder, plus you have the park brake as well, plus you can use engine braking.

At best I would expect a limp home mode if something devious broke in the throttle system.

Cheers

Greg Locock


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RE: Yamaha YZF R1 mode operation

The throttle control systems generally have some level of redundancy related to the accelerator pedal, as was learned in the Toyota situation. It isn't a full backup aircraft-crash-if-it-fails situation, but on the other hand, if the throttle control system misbehaves, lawyers will be waiting to jump on the case.

RE: Yamaha YZF R1 mode operation

Quote (gmaslin)

The throttle only has one function as I understand it and that is to increase/decrease the fuel flow into the engine. All the other functions you describe are already being handled by the ECU. I think you have been overly impressed with this technology. It's logic not magic.

For one thing.. the throttle does nothing related to fuel flow. Throttles control air.

The fact that making the physical throttle plates move is easy but programming the ECU so that the other parameters work correctly is hard is literally the point I've been making since I started posting in this thread.

You underestimate the difficulty in programming an ECU to the reliability and driveability standards that a major manufacturer sets for their products.

RE: Yamaha YZF R1 mode operation

BrianPetersen - the Toyota throttle control system did not misbehave. Some pedals, also used on other makes, would sometimes stick or be slow to return and Toyota was fined for failing to report this to NHTSA. The publicized crash was due to a car dealer using incorrect floor mats in a loaner car, even after being told of interference with the accelerator pedal, combined with a driver who panicked and failed to simply shift the car into neutral. While the Toyota software development was criticized, there was no evidence of reproducible malfunction.

RE: Yamaha YZF R1 mode operation

Yes, we know that now, but it also turned out in the investigation that the pedal sensor has two separate signals to the ECU plus at least one end-of-travel switch signal.

I can totally understand why they do this. It allows the system to be protected against: an unplugged sensor, a broken wire between the sensor and the ECU, a wire shorted to +5V (the power wire to the sensor is in the same wire bundle as the sensor wires, so it's foreseeable for insulation to rub through), a wire shorted to ground, a potentiometer that stops conducting electricity, etc.

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