公开(公告)号：US20020180461A1

公开(公告)日：2002-12-05

申请号：US09872874

申请日：2001-06-04

Applicant: Case Corporation

Inventor： Mohammad Javaid Arshad ,  Alan D. Berger ,  Daniel L. Maierhafer ,  Danley C. Chan

IPC: G01R027/04 ,  G01R027/32

CPC classification number: G01S7/4818 ,  G01S17/10 ,  G01S17/88

Abstract: A hydraulic actuator is disclosed having a cylinder with a piston that is moved by hydraulic fluid. A light guide in one end of the cylinder directs a laser beam into the cylinder, and off the piston where the beam is reflected. The beam then exits the cylinder through at least two light guides connected to two corresponding optical fibers. Each of the optical fibers are joined together into one fiber that carries the reflected beam of light to a photo-diode located remote from the cylinder. A control circuit measures the time of flight of the laser beam.

Abstract translation: 公开了一种液压致动器，其具有带有通过液压流体移动的活塞的气缸。 气缸的一端的导光体将激光束引导到气缸中，并将光束从活塞上反射出来。 然后光束通过连接到两个对应的光纤的至少两个光导件离开圆柱体。 每个光纤被连接在一起，其将反射光束传送到位于远离气缸的光电二极管。 控制电路测量激光束的飞行时间。

公开(公告)号：US20020179824A1

公开(公告)日：2002-12-05

申请号：US09872895

申请日：2001-06-04

Applicant: Case Corporation

Inventor： Mohammad Javaid Arshad ,  Alan D. Berger ,  Daniel L. Maierhafer ,  Danley C. Chan

IPC: G01J001/04

CPC classification number: F15B15/2876

Abstract: A hydraulic actuator is disclosed having a cylinder with a piston that is moved by hydraulic fluid. A laser diode emits a pulse or pulses of light that form laser light beam. These pulses are provided to two or more optical fibers that extend into two or more corresponding cylinders. For each of these cylinders, the optical fiber enters the cylinder at one end of the cylinder and directs a laser beam into the cylinder, and off the piston where the beam is reflected. The reflected beam then exits the cylinder through at least two corresponding optical fibers disposed on either side of the fiber that conducted the light into the cylinder. Each of the optical fibers that receives reflected light is joined together with the others of the optical fibers into one fiber that carries the reflected beam of light to a photo-diode located remote from the cylinder. Each of the photo diodes for each of the two or more cylinders has a corresponding photo diode amplifier. The output of these amplifiers are coupled together and provided to a pulse expansion circuit. The timing circuit that generates the pulse that triggers the laser diode also generates gate pulses for each of the photo diode amplifiers. These gate signals suppress the output of all but one of the photo diode amplifiers. In this manner, the pulse expansion circuit and phase comparator circuits that receive the photo diode amplifier signals will generate an output signal indicative of the time-of-flight of the laser light pulse in only one cylinder at a time. This permits the system to select a specific cylinder and generate a signal indicative of the position of the piston within the cylinder: the time-of-flight of the laser light pulse.

Abstract translation: 公开了一种液压致动器，其具有带有通过液压流体移动的活塞的气缸。 激光二极管发射形成激光束的脉冲或脉冲。 这些脉冲被提供给延伸到两个或更多个相应气缸中的两个或更多个光纤。 对于这些气缸中的每一个，光纤在气缸的一端进入气缸，并将激光束引导到气缸中，并从激光束反射出活塞。 反射光束然后通过设置在光纤的任一侧上的至少两个对应的光纤离开圆筒，该光纤将光导入圆筒。 接收反射光的每个光纤与其他光纤连接在一起，将一个光纤传送到远离气缸的光电二极管。 两个或多个气缸中的每一个的每个光电二极管具有相应的光电二极管放大器。 这些放大器的输出端耦合在一起并提供给脉冲扩展电路。 产生触发激光二极管的脉冲的定时电路也为每个光电二极管放大器产生栅极脉冲。 这些栅极信号抑制除了一个光电二极管放大器之外的所有输出。 以这种方式，接收光电二极管放大器信号的脉冲扩展电路和相位比较器电路将一次产生仅表示一个气缸中的激光脉冲的飞行时间的输出信号。 这允许系统选择特定的气缸并产生指示活塞在气缸内的位置的信号：激光脉冲的飞行时间。