US 12,083,844 B2
Air suspension system and camera cleaning system
Masaki Koyama, Tokyo (JP); Kaito Hotta, Tokyo (JP); Wataru Hatsuse, Tokyo (JP); Tsutomu Ito, Hitachinaka (JP); Yoshinori Kawai, Hitachinaka (JP); and Takahiro Suzuki, Tokyo (JP)
Assigned to Hitachi Astemo, Ltd., Hitachinaka (JP)
Appl. No. 16/980,529
Filed by Hitachi Automotive Systems, Ltd., Hitachinaka (JP)
PCT Filed Oct. 10, 2018, PCT No. PCT/JP2018/037671
§ 371(c)(1), (2) Date Sep. 14, 2020,
PCT Pub. No. WO2019/187258, PCT Pub. Date Oct. 3, 2019.
Claims priority of application No. 2018-061264 (JP), filed on Mar. 28, 2018.
Prior Publication US 2021/0001678 A1, Jan. 7, 2021
Int. Cl. B60G 17/015 (2006.01); B60S 1/60 (2006.01); B60W 10/22 (2006.01); B60W 10/30 (2006.01); F04B 35/04 (2006.01)
CPC B60G 17/0155 (2013.01) [B60S 1/60 (2013.01); F04B 35/04 (2013.01); B60W 10/22 (2013.01); B60W 10/30 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An air suspension system comprising:
an air suspension that supplies and discharges compressed air to adjust a length;
a compressor body in which a piston reciprocates in a cylinder to compress air;
a linear motor that reciprocates the piston;
a tank that is connected to the air suspension or the compressor body and stores compressed air;
a solenoid valve that opens and closes the air suspension or the tank; and
an inverter configured to:
receive an operation command and an estimated load value, the estimated load value being based on a current or future open and closed state of the solenoid valve,
calculate, based on the operation command and the estimated load value, an amount of power to be supplied, and
supply the power to the linear motor to perform position control of the piston;
detect a counter electromotive voltage due to an increase in load;
determine a pressure estimation value of the pressure around the piston based on the counter electromotive voltage; and
change the amount of power supplied to the linear motor perform position control of the piston, the position control being an adjustment of a stroke size of the piston.