Abstract: A compacting machine having a vibrating drum for compaction of ground material includes a controller. The drum is moved over a segment of the ground while a shear modulus and a plastic parameter of the segment of the ground are measured. From the measurements, in particular the value of the shear modulus, values for the frequency and/or the amplitude of the vibration and/or the rolling velocity of the drum are determined. These values are used for adjusting the compacting machine. In the measurement of the shear modulus, two accelerometers are used for determining, during the passing of the segment of the ground, the acceleration of the drum in at least an essentially vertical direction. The amplitude and the phase position of the eccentric system in relation to the acceleration are determined by using, among other things, a pulse sensor. Therefrom, and from fixed data concerning the compacting machine, the shear modulus of the ground is determined by integration of state equations.

Abstract: A roller machine for compacting is provided with control devices for varying the oscillation movement of the body. The movement of the body may be affected by a weight attached thereto. The oscillation of the vibration body is measured. From this measurement, the portion of the oscillation is determined having a frequency corresponding to half the excitation frequency and the portion for other oscillation, in particular the excitation frequency, are also determined. The excitation of the vibrating body is controlled so that the harmonic component having half the excitation frequency will be in a predetermined proportion of the component of the oscillation component. Such control avoids undesired oscillation movement.

Abstract: Estimation of the degree of compaction of a bed when using a compacting machine employs an oscillatory principle. The oscillatory compacting machine is arranged to act on the bed by gravitational force and rapidly alternating horizontal force. The method uses a recorded signal from a horizontally mounted sensor connected to the bearing of the roller drum. The system for performing this method, utilizes a processor to calculate results which are presented by a display unit. Beside the acceleration sensor another sensor and a switch are used in order to enable calculation by the processor of different kinds of averages of the compaction meter value and also for determination of travel speed.

Abstract: Method and apparatus for compacting a layer of material using a compacting machine having at least one drum which is rolled over the layer; the material layer is acted on by gravitational force of the roller and an oscillating force. The latter is the result of applying a rapidly substantially alternating torque to the drum about its axis. The direction of action of the torque is reversed with a high frequency in relation to the frequency with which the direction of travel of the compacting unit is reversed. The invention also embraces means for executing the method wherein the torque on the drum is provided by at least two synchronously operating, rotating eccentric means spaced from the shaft of the drum, and which are adapted such that the forces caused by their synchronous movement can substantially neutralize each other radially to the drum and co-act to form a pure torque on the drum about its shaft.

Abstract: The invention refers to a procedure and a device for measuring the degree of compaction attained when compacting a foundation by means of a vibrating compaction tool. The movement of that part of the compaction tool which rests on the foundation is sensed and analyzed. The time interval elapsing between successive passages of the movement signal through the zero point or other reference level is measured. Alternatively, the ratio between the absolute values of the extreme positive and extreme negative values of the motion in relation to the said level is also measured. By means of the relative magnitudes of these time intervals and amplitude relationships respectively a quantity is formed which comprises a measure of the degree of compaction of the foundation.