Abstract: An area limiting excavation control system in an excavation machine having a front device, includes means for setting in advance, an area where the front device is movable. A control unit calculates the position and posture of the front device based on signals from angle sensors. When the front device is inside the set area near the boundary thereof, the control unit calculates a limit value (a) of a bucket tip speed so that a moving speed of the front device in the direction vertical to the boundary of the set area is restricted, and then modifies the limit value (a) depending on a load pressure of an arm cylinder detected by a pressure sensor. It further calculates, from the limit value (a), a limit value of the component of a boom-dependent bucket tip speed vertical to the boundary of the set area, and then modifies a boom operation signal so that the boom-dependent bucket tip speed will not exceed the above limit value.

Abstract: A setting device for a front control system for a construction machine includes a direct setting switch for instructing a direct teaching setting, a numeral input key consisting of up- and down-keys for instructing a numeral input setting, a setting changeover switch for changing over a setting mode from the direct teaching setting to the numeral input setting, an LED lighting up when the setting changeover switch is pushed, an area limiting switch for starting an area limiting excavation control, an LED lighting up when the area limiting switch is pushed, and a display screen for indicating the position of a bucket end of a front device in terms of a numeral value when the setting changeover switch is not pushed, and indicating the numeral value input with the numeral input with the numeral input setting when the setting changeover switch is pushed.

Abstract: A slope excavation control system for a hydraulic excavator and a slope excavation method using a hydraulic excavator include an external reference 80 which extends horizontally in the direction of advance of a target slope face. A vertical distance hry and a horizontal distance hrx from the external reference to a reference point on a target slope face, and an angle of the target slope face are set by using a setting device. When a front reference provided at a bucket end is aligned with the external reference and an external reference setting switch is depressed, a control unit calculates a vertical distance hfy and a horizontal distance hfx from a body center of the excavator to the external reference, then calculates a vertical distance hsy and a horizontal distance hsx from the body center to the reference point of the target slope face by using the distances hsy and hsx as modification values.

Abstract: An area where a front device (1A) is allowed to move is set beforehand and the operation of the front device is controlled so that the front device will not go out of the set area. For this control process, an arm cylinder speed calculating portion (9d) of a control unit (9) estimates an arm cylinder speed for use in control by taking the sum of a low-frequency component of an arm cylinder speed which is derived through coordinate transformation and differentiation of an arm rotational angle detected by an angle sensor (8b), and a high-frequency component of an arm cylinder speed which is derived from a command value applied from a control lever unit (14b) to a flow control valve (15b) for an arm and a flow rate characteristic of the flow control valve (15b). The control unit controls the operation of the front device with the estimated operating speed.

Abstract: An excavation area setting system for area limiting excavation control in construction machines, with the excavation control being performed to calculate a target speed vector for control of a front device on the basis of a body, modify the target speed vector to limit a moving speed of the front device in the direction toward a boundary of a preset excavation area when the front device comes close to the boundary of the excavation area, and move the front device along the boundary of the excavation area. To set the excavation area, an external reference is installed horizontally outside the hydraulic excavator and a depth from the external reference to the boundary of the excavation area is set by using a setting device. The excavation area is set in a manner matched with the excavation control in which calculation is executed based on the position of the body.

Abstract: A locus control system of hydraulic excavators whereby a target locus for a front device is set beforehand. A control unit calculates a position and posture of the front device based on signals from angle sensors, and calculates a target speed vector of the front device based on signals from control lever devices. Through this calculation process, the control unit maintains the target speed vector as it is when the front device is not near the target locus, and modifies the target speed vector to a vector pointing to a second point on the target locus advanced in the excavating direction by a second distance from a first point located on the target locus at a minimum distance from a tip of the front device, when the front device is near the target locus.

Abstract: In an oil temperature detecting/calculating portion 9p, threshold values T.sub.1, T.sub.2 are set beforehand to divide a range of oil temperature into a first oil temperature range a representing the lowest level, a second oil temperature range b representing a relatively low level, and a third oil temperature range c representing a normal level. The calculating portion 9p executes an alarm control process for making the alarm lamp 14 light up continuously when the detected oil temperature is in the first oil temperature range a, making the alarm lamp 14 blink when it is in the second oil temperature range b, and making the alarm lamp 14 turn out when it is in the third oil temperature range c. This enables a front control system for a construction machine to perform front control accurately and safely even when the temperature of hydraulic oil is low.

Abstract: In a region limiting excavation control system for a construction machine, a region where a front attachment (1A) is movable is set beforehand. A control unit (9) calculates the position and posture of the front attachment based on signals from angle sensors (8a-8c), calculates a target speed vector (Vc) of the front attachment based on signals from control lever units (4a, 4b), and modifies the target speed vector such that the target speed vector is maintained as it is when the front attachment is within the set region but not near the boundary thereof. A vector component (Vcy) of the target speed vector in the direction toward the boundary of the set region is reduced when the front attachment is within the set region near the boundary thereof, and the front attachment is returned to the set region and when the front attachment is outside the set region. As a result, the excavation within a limited region can be implemented efficiently and smoothly.

Abstract: A work area limitation control system for a construction machine which includes a second entrance forbidden area calculating portion which sets a second entrance forbidden area positioned closer to a front device than a first entrance forbidden area. A slowdown control calculating portion calculates distances between two monitoring points and the second and first entrance forbidden areas and modifies operation signals (pilot pressures) depending on the relation of the calculated distances with respect to a slowdown distance.

Abstract: An area where a front device 1A is movable is set in advance. A target speed vector of the front device is modified such that its component in the direction toward a boundary of the set area is reduced, by using signals obtained by reducing operation signals input from control lever units 4a-4c when a mode switch 20 is turned on and the front device is within and near the boundary of the set area, and by using the operation signals as they are when the mode switch 20 is turned off. When the front device is outside the set area, the target speed vector is modified so that the front device is returned to the set area. Thus, excavation within a limited area can be performed efficiently and smoothly, and an operator can select one of an accuracy precedence work mode and a speed precedence work mode at his own discretion.

Abstract: In an area limiting excavation control system for construction machines such as hydraulic excavators, excavation is smoothly and efficiently carried out within a limited area by setting an area beforehand where a front attachment (1A) is movable, calculating the position and posture of the front-attachment (1A) by a control unit (9) based on signals from angle sensors (8a) to (8c), calculating a limit value of the component of the boom-dependent bucket tip speed vertical to the boundary of the set area so that when the front attachment is inside the set area near the boundary thereof, the moving speed of the front attachment in the direction vertical to the boundary of the set area is restricted, and when the front attachment is outside the set area, it is returned to the set area, and modifying a boom operation signal so as to prevent the boom-dependent bucket tip speed from exceeding the limit value.

Abstract: In an excavation area limiting control system for a construction machine for limitingly controlling an area to be excavated, a region where a front device 1A is movable is set beforehand. The position and posture of the front device are calculated based on signals from angle sensors 8a-8c, and a target speed vector of the front device is calculated based on detection signals from control lever units and load pressures detected by pressure sensors 270a to 271b. The target speed vector is modified so that a vector component of the target speed vector in the direction toward the boundary of the set region is reduced when the front device is within the set region near the boundary thereof, and the front device is returned to the set region when the front device is outside the set region. Control signals corresponding to the modified target speed vector are further modified depending on the load pressures and output to proportional solenoid valves 210a to 211b.

Abstract: The present invention relates to an acoustic microscope system having an ultrasonic probe that is driven with a high-frequency burst signal to radiate an ultrasonic signal and that detects the resulting reflected and irradiated waves, a Z-axis moving device that updates the vertical distance Z between the probe and a material of interest for each sampling position, and device for constructing a V(z) curve from the reflection signals obtained at respective sampling positions. The ultrasonic probe of the invention is provided with an acoustic lens, a first ultrasonic transducer for receiving a leaky surface skimming compressional wave reflected from a sample material on one side of the acoustic lens, and a second ultrasonic transducer also provided on the side of the acoustic lens for receiving a leaky surface acoustic wave.