VISTA Knock Definition

This MotoHawk™ block allows a model to use VISTA-type knock detection.

Block ID

VISTA Knock Definition

Library

MotoHawk_lib/Knock Blocks

Description

Overview

This MotoHawk™ block allows a model to use VISTA-type knock detection.

VISTA-type knock detection is very similar to the ProSAK based Knock detection. Both schemes are based upon sampling a knock sensor, filtering it to highlight knocking frequencies and integrating the signal to obtain a representation of energy. Knock for a particular cylinder is sampled in two regions or windows. The first region is referred to as the reference region or noise detection window (NDW). Knock is not expected here and so the energy observed here represents the background noise or reference energy. The second region is where knock is expected. This is referred to as the knock window or the knock detection window (KDW). The duration of the window defines the integration time. The knock signal is only integrated while a window is asserted (started, but not yet stoppped).

Filtering blocks

• VISTA Knock Filter
• Knock IIR Filter Calibration

Window Control blocks

• VISTA Knock Window Set
• VISTA Knock PIPI Window Set
• VISTA Knock Sync Window Set

Result blocks

• VISTA Knock Results
• VISTA Knock Trigger

Configuration blocks

• VISTA Knock Scale Set
• VISTA Knock Output Mode Set (configures the VISTA Knock Trigger)
• VISTA Knock MKICs Mode Set

Pre-configured Filters

The VISTA device supports a number of pre-configured IIR filters. The flexible configuration offered by the above blocks should mean that these blocks are not required. The following blocks relate to the use of these pre-configured IIR filters and don't need to be used if the Filtering blocks above are used.

• VISTA Knock After Noise Calc Mode Set (where the knock calculation is to occur)
• VISTA Knock Fixed Filter Enable Set (enable use of the pre-configured filters)
• VISTA Knock Fixed Gain Set
• VISTA Knock Fixed Cutoff Set

Block Parameters

Parameter Field	Values	Comments/Description
Name	Alpha-numeric text, single-quote enclosed	Name assigned to the device. Used by other blocks to reference this definition. Should be unique and C-legal (no special characters such as spaces, dashes or commas (underscore allowed).
Resource	Drop-down list	The knock detect resources available
Default Sensor Gain	1X/2X	Alters the gain stage of the input amplifier.
Decimal Point Position (0-15)	(0-15)	Select decimal point position from right to determine value range and resolution.
TDC Angles [1 per cylinder]	Bracket[] enclosed array of values for cylinders, respectively	Enter respective cylinder TDC angles, for example  [0 360 180 240]
Knock Sensor Select [1 per cylinder]	Bracket[] enclosed array of values for cylinders, respectively	Enter respective cylinder knock sensor select. For example [0 1 0 1]
PIPI Timing [Start Stop]	[] Array of values	The initial value to be applied e.g. [40 30]. Values are over written by the PIPI Window Set block.
Cylinder Reference Window [Start Stop]	[] Array of values	The initial value to be applied e.g. [20 10]. Values are over written by the Window Set block.
Cylinder Knock Window [Start Stop]	[] Array of values	The initial value to be applied e.g. [-20 -40]. Values are over written by the Window Set block.
Instrumentation Group	Alpha-numeric text, single-quote enclosed	Defines the desired Folder name and hierarchy to be used by suitable Instrumentation Tools. Use "|" character between folder names to delineate subfolder structure.