Auto Stop

[Kobushi]

Honda's manual states that the onyl requirments for auto idle stop are less than 20mph, brake applied, and proper engine temp.

But has anyone noticed that AIS doesn't activate untill your speed has decreased by 2 or 3mph during the brake's application?

If you start braking at 20mph, it won't AIS until 17.
If you start braking at 5, it doesn't AIS untill 3.

To get AIS to kick in AT 19, one must have started applying the brake at 22mph.

At least this is what I have observed on my car.

I regularly drive through an area with a 15mph speed limit, that's how I noticed this.

I suppose Honda wantss to be sure your trying to stop, and not just slowing down a tad.

--Ash

[Insightful Trekker]

It also requires IMA batteries to be in the acceptable range of charge and temperature. And that the vacuum available in the brake booster to be sufficient. One reason that a multiple repeated auto stop sequence is so brief.

It does look like you've gotten a peek at some of the logic in relation to speed and anticipation of an auto stop that this document hints at:

http://www.osti.gov/bridge/product.bibl ... =3&start=0

Page 3, section 5.5, the second paragraph.

HTH :)

[ncnightowl]

If the car is in fuel cut mode, autostop will occur instantly, at least in my experience.

[Insightful Trekker]

Originally Posted by ncnightowl

If the car is in fuel cut mode, autostop will occur instantly, at least in my experience.

Hmmm

An issue of wording maybe?

Fuel cutoff mode can (and will usually) happen at speeds _much_ higher than auto stop will engage.

AFAIK as defined by Honda in some of their literature for older models that incorporated this feature was warm engine, RPM above 1100, and low throttle angle (basically virtually closed).

Specific parameters will likely have changed but the concept is the same. Reduce fuel consumption and emissions without compromising idle recovery. Which is a new "decision" point in the Insight in that you very may well _not_ want to recover to idle RPM. But rather recover to auto stop and effectively allow engine "stalling". The primary input for this decision point on deceleration is brake pedal position.

HTH! :)

[Foxpaw]

Hrm, usually for me autostop won't engage until I apply the brake regardless of speed; however I've had autostop engage without any braking at all, just pressing in the clutch while going downhill through a loop of a cloverleaf.

Originally Posted by Insightful Trekker

http://www.osti.gov/bridge/product.bibl ... =3&start=0

This document states (on page two) that the Insight's motor is a PM DC brushless, but elsewhere I have read that it is 3 phase AC. This page http://www.insightcentral.net/encyclopedia/enmotor.html of the IC Encyclopedia also says it is DC, but then in the last diagram it shows the "3 phase cable connection". DC has no phase. Also in the encyclopedia, on the page about regenerative breaking, it states "During generation, the AC produced by the IMA Motor/Generator is converted by the MDM into DC..." Am I missing something here? Which is it? The internals of the motor look to me like an AC motor, but I'm no expert.

[ext1jdh]

I've noticed that if I come to a stop, and the conditions warrant an auto-stop, and auto-stop does not occur, I can make it happen by pressing the clutch. It's like the computer says "Oh yeah, here goes."

[rslatkin]

Originally Posted by el_vacho

This document states (on page two) that the Insight's motor is a PM DC brushless, but elsewhere I have read that it is 3 phase AC.

I believe it is an AC synchronous motor, which takes three phase AC power and rotates at a speed that corresponds to the frequency of the voltage. This type of motor is also called a "DC brushless" motor for historical reasons.

[Insightful Trekker]

rslatkin is basically correct.

If you want the long technical explanation search the Yahoo group Honda Hybrid for:

From: John Wayland
Date: Tue Jun 25, 2002 5:22pm
Subject: IMA Motor-Generator 101 (was 12 v. battery life)

or PM me with your email address. I've got it as a 47kb MS Wordpad .doc file. Highly technical, but written in a simple to understand form. :)

HTH! :)