Cam and Crank - Crank Encoder v1
Cam and Crank - Crank Encoder v1 — The crank encoder
generates a crank signal depending on the number of teeth, the number of missing
teeth/tooth, duty cycle and speed. The speed can also be a negative number, which
represents reverse rotation. However the current implementation of the cam
decoder is not able to detect reverse rotation.
Library
Simulink® Real-Time™ - Speedgoat
Description
The crank encoder generates a crank signal depending on the number of teeth, the
number of missing teeth/tooth, duty cycle and speed. The speed can also be a
negative number, which represents reverse rotation. However the current
implementation of the cam decoder is not able to detect reverse rotation.
Ports
This driver block has two output and two input ports:
Inputs
-
Speed
Speed in rpm.
-
Duty Cycle
Crank signal duty cycle in %. Default value is 50%. Duty
cycles of 0% and 100% are not allowed.
Outputs
-
Speed
Displays the round information indicating the revolution number within
the two revolution cycle.
Round 1: 0° - 360°
Round 2: 360° - 720°
-
Position
Current crank position in segments. The ratio between number of teeth
and number of segments is 1:2. So the signal-high part and the
signal-low part of a tooth correspond to one segment each. If the duty
cycle is not 50%, these two segments are not of the same size.
Example: A crank with 18 teeths (including 2 missing teeth) has
internally 36 segments.
Parameters
Module Setup Tabulator
-
Configurable I/O Module ID
This parameter associates a code module block with a configurable I/O module setup
block. Set this value to match the Module ID defined in the setup block of the
required configurable I/O module.
-
Channel Vector
A vector of channels this driver block entity will access. You can specify
channels in the range 1-N (N = the number of channels implemented in your specific
configuration file defined in the Setup block). The width of this vector also
defines the subsequent size of some of the following parameters if scalar expansion
applies. With a single block, all the channels of the block are synchronized.
-
Sample Time
Defines the base sample time at which this driver block gets its sample hit. This
parameter can also be set to -1 for inherited
sample time. The units are in seconds.
Crank Encoder Tabulator
-
Number of teeth vector
This parameter defines the number of teeth of the crankshaft. Note
that the number of teeth also includes the missing tooth/teeth.
-
Number of missing tooth/teeth vector
This parameter defines the number of missing tooth/teeth of the crank
shaft.
-
Missing tooth/teeth signal high
This checkbox defines the level during a segment. When the checkbox
is not checked the even segments are high (and the missing tooth low)
whereas when the box is checked the odd segments are high (and the
missing tooth is also high).
-
TDC position vector vector (deg)
This parameter defines the starting offset (starting point) of the
crank encoder in degree.
Input and output Port configuration Tabulator
-
Show round
This parameter defines if the round counter is visible. The signal
indicates the revolution number within the two revolution cycle.
-
Show position
This parameter defines if the position counter is visible. This signal
is the crank encoder signal in segments.
-
Show Duty Cycle
This parameter defines if the Duty Cycle input port is visible. The
default duty cycle is 50%.