Provided are a device and a measuring method for measuring an unbalanced moment on a bottom surface of a circular valve core. The device includes a diverging shaped tube, a water tank, a transparent tube, spring dynamometers, laser sources, a circular valve core, and a high-speed camera with a camera stand. Inner shackles and the laser sources are evenly distributed on an outer side of the circular valve core of the device, the spring dynamometers are connected with the inner shackles and with the outer shackles evenly distributed on an inner wall of the transparent tube. The method records an unbalanced state of the circular valve core under an impact of water flow from different orientations with the high-speed camera on the camera stand, the location of the laser point on the outer wall and a tension force of the spring dynamometer are read to calculate a torque of the circular valve core.

In accordance with an exemplary embodiment, a measurement device is provided that includes an actuator module, a control module, a load cell module, a processing module, and a notification module. The actuator module includes an actuator. The control module includes one or more actuator controllers configured to control the actuator. The load cell module includes one or more motors configured to set orientation of attachments points for the actuator with respect to a component relative to a location of a user. The processing module includes a processor configured to receive and analyze information from the load cell module pertaining to an insertion force for the component. The notification module is configured to provide a notification based on the analyzing performed by the processing module.

Provided are a device and a measuring method for measuring an unbalanced moment on a bottom surface of a circular valve core. The device includes a diverging shaped tube, a water tank, a transparent tube, spring dynamometers, laser sources, a circular valve core, and a high-speed camera with a camera stand. Inner shackles and the laser sources are evenly distributed on an outer side of the circular valve core of the device, the spring dynamometers are connected with the inner shackles and with the outer shackles evenly distributed on an inner wall of the transparent tube. The method records an unbalanced state of the circular valve core under an impact of water flow from different orientations with the high-speed camera on the camera stand, the location of the laser point on the outer wall and a tension force of the spring dynamometer are read to calculate a torque of the circular valve core.

A connection point test apparatus for testing the strength of an association of a connection point (or similar) to an object is disclosed. In one embodiment, the connection point test apparatus includes a body, the body having a surface configured for placement against a surface of the object so that force applied by the body to the surface can be reacted against during operation of the apparatus. The apparatus includes a load transfer assembly operable within a profile of the body, and releasably connectable to the connection point associated with the object. The load transfer assembly is configured operable with the body for generating a force for transfer to the connection point for testing its association to the object. The body is configured so that a portion thereof defines a chamber internal of the body for accommodating a fluid which, when placed under pressure, renders the load transfer assembly operable.

In accordance with an exemplary embodiment, a measurement device is provided that includes an actuator module, a control module, a load cell module, a processing module, and a notification module. The actuator module includes an actuator. The control module includes one or more actuator controllers configured to control the actuator. The load cell module includes one or more motors configured to set orientation of attachments points for the actuator with respect to a component relative to a location of a user. The processing module includes a processor configured to receive and analyze information from the load cell module pertaining to an insertion force for the component. The notification module is configured to provide a notification based on the analyzing performed by the processing module.

An artificial fingertip sliding tactile sensor includes a PVDF film, a rubber fingertip, a filling liquid, a sealing plug, a hydraulic sensor, a housing, an inner framework, and strain gauges. The rubber fingertip is a hemispherical cavity. The PVDF film is attached to the outside of the rubber fingertip. The sealing plug seals the rubber fingertip, and the hydraulic sensor is installed at the bottom of the sealing plug. The main body of the housing is a rigid cylindrical structure. The top of the housing is provided with a circular opening, and the bottom of the housing is a flange-like structure. Four circular through holes are uniformly distributed on the flange-like structure. The inner framework includes a cylindrical head, a vertical strain rod and a base. The strain gauges are respectively attached on four sides of the vertical strain rod and adjacent to the base.

An artificial fingertip sliding tactile sensor includes a PVDF film, a rubber fingertip, a filling liquid, a sealing plug, a hydraulic sensor, a housing, an inner framework, and strain gauges. The rubber fingertip is a hemispherical cavity. The PVDF film is attached to the outside of the rubber fingertip. The sealing plug seals the rubber fingertip, and the hydraulic sensor is installed at the bottom of the sealing plug. The main body of the housing is a rigid cylindrical structure. The top of the housing is provided with a circular opening, and the bottom of the housing is a flange-like structure. Four circular through holes are uniformly distributed on the flange-like structure. The inner framework includes a cylindrical head, a vertical strain rod and a base. The strain gauges are respectively attached on four sides of the vertical strain rod and adjacent to the base.

The invention concerns a method for estimating an external force acting on an electrohydrostatic actuator, the actuator comprising a ram including a first chamber, a second chamber and a piston located between the first chamber and the second chamber, a pump capable of injecting fluid into the chambers for controlling a movement of the piston, and an electric motor driving the pump, the method comprising steps of: estimating, by means of at least one state observer (21, 22), a dynamic component and a static component of a difference in equivalent fluid pressure between the first chamber and the second chamber from a rotational speed of the electric motor, a position of the piston and a supply current of the electric motor, estimating the external force by means of a post-processing module (23) as a combination of the estimated dynamic component and static component of the difference in fluid pressure.

A zero-strain soil pressure sensor includes a shell provided with a hydraulic oil cavity and a cavity located below the hydraulic oil cavity, a processor, an outer elastic film arranged at the upper end of the hydraulic oil cavity, an inner elastic film arranged between the hydraulic oil cavity and the cavity, an outer strain bridge circuit connected with the outer elastic film, an inner strain bridge circuit connected with the inner elastic film, a piston communicated with the hydraulic oil cavity, and a driving mechanism connected with the piston. The outer strain bridge circuit, the inner strain bridge circuit and the driving mechanism are electrically connected with the processor. The invention has the beneficial effect that the piston is driven by the driving mechanism to control the oil pressure in the hydraulic oil cavity, external soil pressure is balanced through the oil pressure to keep the outer elastic film in an non-deforming state all the time, and only the inner elastic film is deformed, so that the soil arch effect and soil displacement are avoided, and thus the liquid pressure measured by the inner elastic film is the soil pressure, and the measurement result is more accurate.

A zero-strain soil pressure sensor includes a shell provided with a hydraulic oil cavity and a cavity located below the hydraulic oil cavity, a processor, an outer elastic film arranged at the upper end of the hydraulic oil cavity, an inner elastic film arranged between the hydraulic oil cavity and the cavity, an outer strain bridge circuit connected with the outer elastic film, an inner strain bridge circuit connected with the inner elastic film, a piston communicated with the hydraulic oil cavity, and a driving mechanism connected with the piston. The outer strain bridge circuit, the inner strain bridge circuit and the driving mechanism are electrically connected with the processor. The invention has the beneficial effect that the piston is driven by the driving mechanism to control the oil pressure in the hydraulic oil cavity, external soil pressure is balanced through the oil pressure to keep the outer elastic film in an non-deforming state all the time, and only the inner elastic film is deformed, so that the soil arch effect and soil displacement are avoided, and thus the liquid pressure measured by the inner elastic film is the soil pressure, and the measurement result is more accurate.