The invention relates to a measuring arrangement for measuring a position, in particular a verticality, of a vertically adjustable and lowerable working apparatus with respect to an upper fixed point, with at least one measuring cable which is on the one hand connected to the vertically adjustable working apparatus and on the other hand extends towards the fixed point, at least one measuring means which is connected to the corresponding measuring cable and designed to measure an angle of inclination of the measuring cable relative to a vertical measurement axis and is arranged in a connection region between the measuring cable and the working apparatus, and at least one connecting means which is arranged between the measuring means and the working apparatus and designed to keep the measuring means torsion proof about the vertical measurement axis and at the same time capable of being angled with respect to the vertical measurement axis on the working apparatus. According to the invention provision is made in that the connecting means has a connecting tube which is arranged coaxially to the vertical measurement axis, and in that the connecting tube is designed so as to be torsion proof about the vertical measurement axis and deflectable with respect to the vertical measurement axis.

The invention relates to a measuring arrangement for measuring a position, in particular a verticality, of a vertically adjustable and lowerable working apparatus with respect to an upper fixed point, with at least one measuring cable which is on the one hand connected to the vertically adjustable working apparatus and on the other hand extends towards the fixed point, at least one measuring means which is connected to the corresponding measuring cable and designed to measure an angle of inclination of the measuring cable relative to a vertical measurement axis and is arranged in a connection region between the measuring cable and the working apparatus, and at least one connecting means which is arranged between the measuring means and the working apparatus and designed to keep the measuring means torsion proof about the vertical measurement axis and at the same time capable of being angled with respect to the vertical measurement axis on the working apparatus. According to the invention provision is made in that the connecting means has a connecting tube which is arranged coaxially to the vertical measurement axis, and in that the connecting tube is designed so as to be torsion proof about the vertical measurement axis and deflectable with respect to the vertical measurement axis.

An apparatus (100) to trace pile set during pile driving comprises a panel (110) for attachment to a pile (150); a holding mechanism (120) to hold a writing instrument (160) against the panel (110) to trace the pile set for series of blows during the pile driving; a sliding mechanism (130) to provide lateral movement across the panel (110) for the holding mechanism (120) after each blow during the pile driving; and a platform (140) to allow the sliding mechainsm (130) to slide freely in horizontal direction.

An apparatus (100) to trace pile set during pile driving comprises a panel (110) for attachment to a pile (150); a holding mechanism (120) to hold a writing instrument (160) against the panel (110) to trace the pile set for series of blows during the pile driving; a sliding mechanism (130) to provide lateral movement across the panel (110) for the holding mechanism (120) after each blow during the pile driving; and a platform (140) to allow the sliding mechainsm (130) to slide freely in horizontal direction.

The invention relates to a method of operating a mobile work machine with a ground pressure limitation and to a corresponding work machine. A maximum permitted ground pressure is compared with an actually present ground pressure.

A method of recognizing obstacles on operation of a vibratory pile driver of a work machine includes monitoring an acceleration signal of the vibratory pile driver during operation of the vibratory pile operator and analyzing the acceleration signal to determine the presence of an obstacle. The acceleration signal may be monitored over a time period which is determined based on an excitation frequency of the vibratory pile driver. The analysis may include comparing negative and positive half-waves of the acceleration signal. Responsive to the analysis indicating an obstacle, a system operator may be alerted, and/or operation of the vibratory pile driver may be adjusted via controller intervention.

A non-contact strain and/or displacement measurement system for use with structural objects having an optical device, a data store and an image arrangement that is fixed relative to the structural object to be tested, the optical device including an image receiving device for receiving visual images and the data store being configured to record the received visual images, the image receiving device being spaced from the image arrangement by an optical spacing such that the image receiving device has a visual range that includes a portion of the structural object and the image arrangement being within the portion, the image arrangement having at least one image element wherein movement of the at least one image element during a measurement period provides image data to calculate structural object strain and/or structural object displacement.

There is provided a piling hammer comprising a linear electric machine comprising a mover connected to a ram block for striking a pile, a processor operatively connected to the linear electric machine and configured to determine a recoiled kinetic energy from striking the pile using a ram block connected to a mover of the linear electric machine, determining at least a portion of the determined recoiled kinetic energy for regenerative braking the of the mover to a peak position, control the linear electric machine to decelerate the mover to the peak position based on the determined at least a portion of the determined recoiled kinetic energy.

A system for installing an array of pilings for an array of solar panels is highly accurate and efficient. The system includes a horizontal laser and a rotating vertical laser that are mounted on a first piling and aligned with a target on a second piling on the opposite side of the array. An alignment template is placed against a piling and aligned with the vertical rotating laser. The aligned template provides a designated location where the next piling is driven. A hammer target on the pile driver allows the installer to precisely install the next piling. After installation, the next piling is measured for accuracy and if errors are found, an alignment bracket is used to correct the error. The process is repeated until the array of pilings is complete.

A method for optimizing the driving of a pile into the ground by a pile-driving machine using a hammer ram; moving a block for driving the pile towards the end of the pile with an impact energy (W.sub.kin); determining a kinetic variable (Q1) of the impact, proportional to the kinetic energy of the block, when the block is moving towards the pile in the pile driving direction; determining the value of a kinetic variable (Q3) of the return motion, proportional to the kinetic energy of the block, when returning, after an impact on the pile, in a direction opposite to the pile driving direction; calculating a kinetic variable ratio (Q1/Q3); comparing (Q1/Q3) with a predetermined target value (Q1/Q3.sub.tav) for (Q1/Q3), producing the shortest possible total pile driving time (t.sub.tot); adjusting the impact energy (W.sub.kin) of the next impact so (Q1/Q3) of the next impact is changed towards (Q1/Q3.sub.tav).