Toyota Camry Hybrid AHV40 Manual page 185

CH-84
b. Torque Sensor Operation
i) Straight-line Driving
If the vehicle is driven straight and the driver dose not turn the steering wheel, the specified voltage
that is output at this time is determined by the ECU to indicate the neutral position of the steering.
Therefore, it dose not apply current to the motor.
ii) When Steering
When the driver turns the steering wheel, a relative angle difference is created between the rotor
portions of the resolvers 1 and 2, only in the amount that is equivalent to the twisting of the torsion
bar. The stator portions of the resolvers 1 and 2 receive the angles of the rotors in the form of electric
signals and output them to the EPS ECU. Based on these input signals, the EPS ECU calculates the
relative angle difference between the angles detected by the two resolvers. The EPS ECU calculates
the torque value based on that difference. Then, the EPS ECU calculates the assist current based on
the calculated torque value and vehicle speed. Based on the information obtained from the rotation
angle sensor, the EPS ECU actuates the motor at a predetermined current.
Rotor Portion
(Resolver 1)
Rotor Portion
(Resolver 2)
"
Torque Sensor Output Image Diagram
Resolver 1
Output
Resolver 2
Output
CHASSIS - STEERING
Relative Angle Difference
A
Small Steering Torque
Stator Portion
(Resolver 1)
Stator Portion
(Resolver 2)
Large Steering Torque
277CH156
277CH157