Chinese Academy of Geological Sciences

Chinese Academy of Sciences

Dongsheng Sun

Qunce Chen

Xiaolong Li

Junfeng Zhang

Quan Li

Ming Jin

Chongyuan Zhang

Junzhi Zhang

Lifang Wang

Xianghui Qin

Chengkun He

Yuehui Yang

Wen Meng

Bangchen Wu

Awei Li

A configuration control method for an electronic mechanical brake-by-wire system is Provided. The control method includes: acquiring a first actual output torque measured by the first torque sensor and a second actual output torque measured by the second torque sensor; if a received signal is a brake loading signal, separately comparing a first difference with an initial torque difference and a maximum torque difference when a motor fails to obtain a comparison result, where the first difference is an absolute value of a difference between the first actual output torque and the second actual output torque; and controlling the first motor and the second motor according to the comparison result to complete brake loading by means of the brake actuator. Also provided is a configuration control system for an electronic mechanical brake-by-wire system. The control method and the control system can achieve synchronous and precise control of a brake force.

Configuration control method and control system for electronic mechanical brake-by-wire system

A method and a device for determining fracture closure pressure based on hydraulic fracturing are provided. The method includes: determining a leak-off volume of a fluid during a refrac cycle according to a fluid pressure during the refrac cycle; generating a stiffness change curve during the refrac cycle according to the leak-off volume of the fluid and the fluid pressure; and determining the fracture closure pressure according to the stiffness change curve. A hydraulic coupling mechanism and change characteristics during a pressure attenuation process are quantitatively characterized, and characteristic response corresponding to a pressure drop curve before and after the fracture closure are accurately described, thereby providing a method and a device for determining fracture closure pressure with clear physical significance and objective effectiveness.

Method and device for determining fracture closure pressure based on hydraulic fracturing

The present disclosure relates to the technical field of rock mechanics, and in particular to a method for accurately measuring a reopening pressure of hydraulic fracturing induced fracture in a deep borehole. The method includes: pumping a fluid into a sealed inner space of a drilling pipe for energy storage; and opening a valve at a lower end of the drilling pipe such that energy is released from the fluid in the inner space of the drilling pipe under the action of pressure to inject the fluid into a test interval. In the method according to the present disclosure, a fluid is pumped into an inner space of a drilling pipe so that the inner space of the drilling pipe is used as a high-pressure fluid pump to inject the fluid in the inner space of the drilling pipe to the test interval until the closed fracture is reopened.

Method for accurately measuring reopening pressure of hydraulic fracturing induced fracture in deep borehole

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Beijing, China

Dongsheng Sun