Pedal Assist System

Lynx offers an advanced pedal assistant system with cadence and torque input with the possibility to activate "human watts" feature to fulfill the most demanding users' requirements.

In the default state, only the cadence sensor is used (but cadence is implemented in all the other modes). Digital pulses from its input are normalized in the Tachopas block and its output is read as cadence (normalized signal 0-1). Cscpas block is there for optional shaping of the cadence signal. The last block before the state machine is a multiplier. It scales the cadence signal by the value defined by the parameter paslvl (defines the amount of PAS support). To the state machine is fed also information about torque. Its input is value 1 in the case where no torque sensor is mapped to the system. But before it reaches the state machine, the torque signal is multiplied by pastrq value (defines torque for PAS support). Motor mode 3 (with the limit for maximal torque - defined by sig_toruqe) is used for the driver. Signal sig_pas defines driver cmd.

This function is activated if in_cadence is mapped to a valid physical input

PAS default (basic) configuration:

Variables

info

The mentioned variables are located in the folder /lock.

Parameter	Description	Range
pasopts	PAS options	1 - Enables reverse pedaling brake (PAS brake)
trqgain	Defines torque multiplier (for human_trq calculation)	[-]

State variable	Description	Unit
human_trq	Indicates torque signal for human watts calculation	[-]
human_watts	Indicates human watts signal (cadence x human_trq x 10)	[-]
paslvl	Indicates actual value of paslvl multimplier (this changes with maps)	[-]

PAS with torque sensor

This is an advanced option of PAS where also information about forces acting on pedals is processed. The raw analog signal is normalized in asctorque block, then multiplied by trqlvl value (to reduce global motor torque). The resultant signal then follows the same path as in the default PAS configuration.

This advanced PAS function is activated if in_torque is mapped to a valid physical input

PAS with human watts

The latest addition to the PAS features. It combines cadence and torque signals to achieve better torque control during fast pedaling.

The analog torque signal path is the same as in the previous section. The signal after trqlvl multiplier is fed to another multiplier with the factor defined by trqgain (human_trq). Then the output signal is merged with the cadence signal and multiplied by a factor of ten. The resultant signal is called human_watts. Its raw value is normalized in ascwatts block.

The final block of this advanced fusion is the Max value selector. It sends to its output the signal with the higher value (direct torque from torque sensor or human watts). The output signal then follows the same path as in the default PAS configuration

This advanced PAS function is activated if in_torqu is mapped to a valid physical input and trqgain is not equal to zero