Patent Description:
One phenomenon encountered during slip form paving of concrete structures when using an oscillating beam behind a slip form mold is the formation of a "roll" of not yet hardened concrete material immediately in front of the oscillating beam. There is a need for improved apparatus and methods of monitoring and controlling such a "roll" of not yet hardened concrete material.

<CIT> and <CIT> describe a slip form paving machine, comprising a machine frame, a plurality of ground engaging wheels or tracks, and front and rear height adjustable lifting columns supporting the machine frame from the ground engaging wheels or tracks. The lifting columns are adjustable to adjust a longitudinal inclination of the machine frame in a paving direction. A slip form mold is supported from the machine frame for molding a mass of concrete into a formed not yet hardened concrete slab as the paving machine moves forward in the paving direction. An oscillating beam is supported from the machine frame behind the slip form mold for engaging and oscillating transversely to the paving direction upon an upper surface of the formed not yet hardened concrete slab to smooth the upper surface.

<CIT> and <CIT> disclose an adjustable width mold for a slipform paver including a center portion and left and right sideform assemblies.

In one embodiment a slip form paving machine includes a machine frame, a plurality of ground engaging wheels or tracks, and front and rear height adjustable lifting columns supporting the machine frame from the ground engaging wheels or tracks, the lifting columns being adjustable to adjust a longitudinal inclination of the machine frame in a paving direction. A slip form mold is supported from the machine frame for molding a mass of concrete into a formed not yet hardened concrete slab as the paving machine moves forward in the paving direction. An oscillating beam is supported from the machine frame behind the slip form mold for engaging and oscillating transversely to the paving direction upon an upper surface of the formed not yet hardened concrete slab to smooth the upper surface. A roll size sensor is configured to detect a size of a roll of not yet hardened concrete created in front of the oscillating beam.

In a further embodiment the roll size sensor may be configured to detect a parameter corresponding to a cross-sectional dimension of the roll.

In any of the above embodiments the roll size sensor may be a roll height sensor and the parameter may be a vertical distance from the machine frame to a top of the roll or the roll size sensor may be a roll width sensor and the parameter may be a horizontal distance from the machine frame to a side of the roll.

In any of the above embodiments the roll size sensor may include at least two discrete roll height sensors spaced across a width of the machine frame or the roll size sensor may include at least two discrete roll width sensors spaced across the width of the machine frame.

In any of the above embodiments the roll size sensor may include at least one scanning laser sensor configured to scan an exterior of the roll across a continuous portion of a width of the machine frame.

In any of the above embodiments the machine may include a controller configured to receive a sensor signal from the roll size sensor and to generate a command signal to an actuator to adjust the longitudinal inclination of the machine.

In any of the above embodiments the controller may be further configured to determine the size of the roll as an average size over an interval of time.

In any of the above embodiments the controller may be further configured to predict the size of the roll based at least in part upon a rate of change of the sensor signal.

In any of the above embodiments the controller may be further configured to lower the front end of the machine frame relative to the rear end to decrease the size of the roll and to raise the front end of the machine frame relative to the rear end to increase the size of the roll.

In any of the above embodiments the controller may be further configured to adjust the longitudinal inclination of the machine frame by adjusting both the front and rear lifting columns thereby tilting the machine frame about a rotational axis adjacent a rear edge of the oscillating beam so that a height of the upper surface of the formed not yet hardened concrete slab behind the oscillating beam is not changed.

In any of the above embodiments the controller may be further configured to adjust the longitudinal inclination of the machine frame by adjusting both the front and rear lifting columns simultaneously.

In any of the above embodiments the controller may be configured to: (a) monitor a sensor signal from the size sensor; (b) based at least in part on the sensor signal, determine a current or a predicted deviation of the size of the roll of not yet hardened concrete from a desired size; and (c) generate a command signal to adjust the longitudinal inclination of the machine frame in a direction to counteract the deviation.

The controller may be further configured to: after step (c) repeat steps (a) and (b) after a lag time interval sufficient to allow the adjusting of step (c) to result in a change in the size of the roll; and further adjust the longitudinal inclination of the machine frame in a direction to counteract any further determined current or predicted deviation of the size of the roll.

In any of the above embodiments the lag time interval may be based on a time necessary for the paving machine to travel a specified distance in the paving direction.

In any of the above embodiments the machine may further include a concrete supply height sensor arranged to detect a height of a mass of concrete in front of the slip form mold and a swelling sensor arranged to detect a height of the formed not yet hardened concrete slab behind the slip form mold, wherein the controller is further configured to generate the command signal at least in part based upon signals from the concrete supply height sensor and/or the swelling sensor.

In any of the above embodiments the machine may further include a front stringline sensor, a front sensor actuator arranged to adjust a vertical position of the front stringline sensor relative to the machine frame, a rear stringline sensor, a rear sensor actuator arranged to adjust a vertical position of the rear stringline sensor relative to the machine frame, and a controller configured to receive a roll size sensor signal from the roll size sensor and to send command signals to the front and rear sensor actuators to cause an adjustment in the longitudinal inclination of the machine frame.

In any of the above embodiments the machine may further include a front sensor actuator position sensor arranged to generate a position signal representative of a position of the front stringline sensor and a rear sensor actuator position sensor arranged to generate a position signal representative of a position of the rear stringline sensor.

In any of the above embodiments the front and rear sensor actuators may be front and rear hydraulic smart cylinders and the front and rear sensor actuator position sensors may be integrated in the front and rear hydraulic smart cylinders, respectively.

In any of the above embodiments the front and rear sensor actuators may be front and rear rotary spindles powered by rotary motors, and the front and rear sensor actuator position sensors may be rotational position sensors.

A method of controlling a slip form paving machine constructed according to any of the above embodiments may include steps of: (a) monitoring with at least one sensor at least one parameter indicative of a current or a predicted size of a roll of not yet hardened concrete created in front of the oscillating beam and generating at least one sensor signal representative of the at least one parameter; (b) based at least in part on the at least one sensor signal, determining with a controller a current or a predicted deviation of the size of the roll of not yet hardened concrete from a desired size and generating a corresponding command signal; and (c) in response to the command signal, automatically adjusting the longitudinal inclination of the machine frame in a direction to counteract the deviation.

In the above method the at least one parameter may correspond to a cross-sectional dimension of the roll.

In any of the above methods the cross-sectional dimension may include a height of the roll or a width of the roll.

In any of the above methods step (a) may further comprise monitoring the size of the roll as an average size over an interval of time.

In any of the above methods step (a) may further comprise monitoring the size of the roll in at least two locations across a width of the paving machine.

In any of the above methods step (c) may further comprise lowering the front end of the machine frame relative to the rear end to decrease the size of the roll and raising the front end of the machine frame relative to the rear end to increase the size of the roll.

In any of the above methods step (c) may further comprise adjusting the longitudinal inclination of the machine frame by adjusting both the front and rear lifting columns and thereby tilting the machine frame about a rotational axis adjacent a rear edge of the oscillating beam so that a height of the upper surface of the formed not yet hardened concrete slab behind the oscillating beam is not changed.

In any of the above methods step (b) may further comprise determining the predicted size based at least in part upon a rate of change of the at least one parameter.

Any of the above methods may further include after step (c) repeating steps (a) and (b) after a lag time interval sufficient to allow the adjusting of step (c) to result in a change in the size of the roll, and further adjusting the longitudinal inclination of the machine frame in a direction to counteract any further determined current or predicted deviation of the size of the roll.

In any of the above methods the lag time interval may be based on a time necessary for the paving machine to travel a specified distance in the paving direction.

In any of the above methods the at least one parameter may include a height of a mass of concrete immediately in front of the slip form mold.

In any of the above methods the at least one parameter may include a height of the formed not yet hardened concrete slab immediately behind the slip form mold.

Numerous objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a review of following description in conjunction with the accompanying drawings.

The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed in the following detailed description.

Referring now to the drawings and particularly to <FIG> a slip form paver machine is shown and generally designated by the number <NUM>. The machine <NUM> is configured to move in a paving direction <NUM> across a ground surface <NUM> for spreading, leveling and finishing concrete into a finished concrete structure <NUM> having a generally upwardly exposed concrete surface <NUM> and terminating in lateral concrete sides such as <NUM>.

The slip form paver machine <NUM> includes a main frame <NUM> and a slip form paver mold <NUM> supported from the main frame <NUM>. Left and right side form assemblies <NUM> are connected to the slip form paver mold <NUM> to close the slip form paver mold <NUM> on the left and right sides to form the lateral concrete sides such as <NUM> of the finished concrete structure <NUM>. The slip form paver machine <NUM> shown in <FIG> is an inset type slip form paver apparatus.

The main frame <NUM> is supported from the ground surface by a plurality of ground engaging units such as <NUM>, which in the illustrated embodiment are tracked ground engaging units <NUM>. Wheeled ground engaging units may also be used. Each of the ground engaging units <NUM> is connected to the main frame <NUM> by a lifting column such as <NUM> which is attached to a swing arm such as <NUM>. An operator's station <NUM> is located on the main frame <NUM>. A plow or spreader device <NUM> is supported from the main frame <NUM> ahead of the slip form paver mold <NUM>. A spreading auger may be used instead of the plow <NUM>. Behind the slip form paver mold <NUM> a dowel bar inserter apparatus <NUM> may be provided. Behind the dowel bar inserter apparatus <NUM> an oscillating beam <NUM> and/or a super smoother apparatus <NUM> may be provided. If no dowel bar inserter apparatus <NUM> is used the oscillating beam <NUM> and/or the super smoother apparatus <NUM> may be provided behind the slip form paver mold <NUM>.

It will be appreciated that many slip form pavers do not include the dowel bar inserter apparatus <NUM>. The further schematic illustration of <FIG> shows the slip form paver machine <NUM> without the dowel bar inserter apparatus <NUM>. Also it will be appreciated that some slip form pavers do not include the oscillating beam <NUM>.

<FIG> schematically shows the slip form paving machine <NUM> including the oscillating beam <NUM> but not including a dowel bar inserter <NUM>. It will be understood that the dowel bar inserter <NUM> could be placed between the slip form mold <NUM> and the oscillating beam <NUM>.

In <FIG> the lifting columns <NUM> are designated as 32F and 32R for the front and rear lifting columns, respectively. The tracks <NUM> are designated as 30F and 30R for the front and rear tracks, respectively. It will be understood that there are two front lifting columns 32F on left and right sides of the machine <NUM>, supporting the machine frame <NUM> from two front tracks 30F. Similarly, there are two rear lifting columns 32R supporting the machine frame <NUM> from two rear tracks 30R. In both <FIG> and <FIG> the slip form paving machine <NUM> is illustrated as a four-track machine having front and rear tracked ground engaging units <NUM> on each of the left and right sides of the machine. It will be understood that the various features disclosed herein are equally applicable to a two-track paving machine, such as for example the Wirtgen Model SP 62i, having one long crawler track on each of the left and right sides of the machine frame, with a front and a rear lifting column on each side of the machine frame supporting the machine frame from each of the two tracks.

Each of the lifting columns is constructed as a telescoping member and may include a hydraulic smart cylinder actuator such as 46F and 46R seen in <FIG>. Extension and retraction of the actuators 46F and/or 46R causes extension and retraction of the lifting columns 32F and 32R and can raise or lower the machine frame <NUM> relative to the ground surface <NUM> and/or can adjust a longitudinal and/or transverse inclination of the machine frame <NUM> relative to the ground surface <NUM>. Each of the hydraulic smart cylinders may include an integrated extension sensor such as 48F and 48R to allow precise monitoring and control of the extension of the lifting columns <NUM>. Optionally the lifting columns may include conventional hydraulic cylinders and separate associated extension sensors.

The plow or spreader device <NUM> identified in <FIG> is shown schematically in <FIG> as an auger type spreader device <NUM>.

Behind the auger type spreader device <NUM> is a height adjustable concrete supply gate <NUM>. The gate <NUM> is supported from the machine frame <NUM> by one or more gate actuators <NUM> for adjusting a height of the gate <NUM> relative to the machine frame <NUM>. The gate actuators <NUM> may also be constructed as hydraulic smart cylinders having integrated extension sensors <NUM> to allow precise monitoring and control of the extension of the height of the gate <NUM>. Optionally the gate actuators <NUM> may include conventional hydraulic cylinders and may have separate associated extension sensors.

Between the gate <NUM> and the slip form mold <NUM> are a plurality of vibrators <NUM> which are configured to be submerged in the concrete mass from which the slab <NUM> is formed to aid in compacting the concrete as the slip form mold <NUM> moves over the concrete mass.

In the paving process a mass of concrete material 16A is dumped on the ground surface <NUM> ahead of the paving machine <NUM>. This is typically done with a series of dump trucks (not shown) dumping their loads of wet concrete onto the ground surface, so the supply of concrete material 16A occurs in a series of sequential dumps of material. Alternatively, the concrete mass may be supplied by a side feeder, a shuttle buggy, a placer-spreader or other known concrete supply means. The material 16A is spread transversely across the width of the paving machine <NUM> by the spreader device <NUM>. The height of the concrete supply gate <NUM> is adjusted to control the amount of concrete material 16B directly in front of the slip form mold <NUM>. With the aid of the vibrators <NUM> the concrete material is consolidated and semi-liquified and the slip form mold <NUM> moves across the concrete material 16B to form it into the concrete slab <NUM>. Immediately behind the slip form mold <NUM> there may be some swelling in height of the newly formed slab in the area 16C. The swelling of the concrete slab causes an increase in the height of the slab as represented in <FIG> by the dimension <NUM> which is the increase in height of the slab above the bottom edge <NUM> of the mold <NUM>. Immediately ahead of the oscillating beam <NUM> a roll 16D of concrete material may form.

The oscillating beam <NUM> is supported from the machine frame <NUM> behind the slip form mold <NUM> for engaging and oscillating transversely to the paving direction <NUM> upon the upper surface <NUM> of the formed not yet hardened concrete slab <NUM> to smooth the upper surface <NUM>. The upper surface <NUM> may be further smoothed by the action of the super smoother <NUM> which is a large automated smoothing trowel which moves transversely across the width of the slab <NUM> while reciprocating forward and rearward.

The direction of the paving machine <NUM> and the height of the formed concrete slab <NUM> may be controlled with a grade control system. One such grade control system is a stringline type grade control system in which a stringline <NUM> is constructed adjacent the location of the planned concrete slab. Such a stringline <NUM> may be constructed in advance of the paving operation by a surveyor who places the stringline at a known geographic location and at a known elevation. The machine <NUM> may then use the stringline <NUM> as a physical reference to guide both the path of the machine <NUM> and to control the height of the machine <NUM> relative to the ground surface <NUM> so as to control the height of the upper surface <NUM> of the formed concrete slab <NUM>.

Although the paving machine <NUM> is primarily described in the present disclosure in the context of a stringline type grade control system, it will be understood that some aspects of the improved paving machine <NUM> disclosed herein may be used with other types of grade control systems such as a satellite based grade control system (GPS or GNSS) or a Total Station type grade control system or a hybrid combination of a satellite based grade control system and a Total Station type grade control system. In <FIG> a satellite based grade control system is schematically indicated by a satellite <NUM> and by receivers <NUM> and <NUM> on the machine <NUM> which may be satellite signal receivers <NUM> and <NUM>. Also, in <FIG> two Total Station laser transmitters are schematically represented as 310A and 310B, and in that case the receivers <NUM> and <NUM> may be Total Station reflectors/receivers of a known type.

The machine <NUM> may include front and rear stringline sensors 60F and 60R. Although the machine <NUM> may have front and rear stringline sensors 60F and 60R on each side of the machine (left and right), it will be understood that on some occasions a stringline <NUM> may only be constructed for one side of the machine <NUM> in which case the elevation of the opposite side of the machine <NUM> may be controlled via a cross-slope sensor which detects the cross-slope of the machine frame <NUM> relative to gravity.

Each of the front and rear stringline sensors 60F and 60R may be constructed in a known manner as schematically shown in <FIG>. The front and rear stringline sensors 60F and 60R may be supported from the machine frame <NUM> by front and rear sensor actuators 62F and 62R, respectively. The actuators 62F and 62R are configured to adjust a vertical position of the front and rear stringline sensors 60F and 60R, respectively, relative to the machine frame <NUM>.

A front sensor actuator position sensor 64F may be associated with the front sensor actuator 62F and configured to generate a position signal representative of the vertical position of the front stringline sensor 60F relative to the machine frame <NUM>. A rear sensor actuator position sensor 64R may be associated with the rear sensor actuator 62R and configured to generate a position signal representative of the vertical position of the rear stringline sensor 60R relative to the machine frame <NUM>.

In one embodiment the front and rear sensor actuators 62F and 62R may be front and rear hydraulic smart cylinders 62F and 62R and the front and rear sensor actuator position sensors 64F and 64R may be integrated in the front and rear hydraulic smart cylinders 62F and 62R, respectively. Optionally the actuators 62F and 62R may include conventional hydraulic cylinders and may have separate associated extension sensors.

In another embodiment the front and rear sensor actuators 62F and 62R may be front and rear rotary spindles powered by rotary motors and the front and rear sensor actuator position sensors 64F and 64R may be rotational position sensors.

<FIG> schematically shows the front stringline sensor 60F supported by front sensor actuator 62F which is shown as a hydraulic smart cylinder 62F. It will be understood that the other stringline sensors and associated sensor actuators may be similarly constructed. The sensor 60F includes a wand <NUM> which engages the stringline <NUM>. The sensor wand <NUM> may be biased to ride along the underside of the stringline <NUM>. Any change in height of the machine frame <NUM> relative to the stringline <NUM> will cause a rotation of the wand <NUM> about sensor axis <NUM> and will create a sensor signal which can be used as a basis for adjustment of the position of the associated lifting column actuator 46F to maintain a desired elevation of the machine frame <NUM> relative to the stringline <NUM>. The sensor 60F will typically be initially set up with the wand <NUM> in a "zero" position with the machine frame <NUM> at the desired height relative to the stringline <NUM>. The "zero" position is preferably a horizontal position of the wand <NUM>. Then if the wand <NUM> is rotated up or down a corresponding adjustment can be made in the lifting column position to maintain a desired elevation of the machine frame <NUM> and thus of the resulting concrete slab <NUM> relative to the stringline <NUM>. If it is desired to adjust a height of the machine frame <NUM> and the concrete slab <NUM> relative to the stringline <NUM> this may be done by adjusting the vertical position of the sensor 60F relative to the machine frame <NUM> using the front sensor actuator 62F. Because the sensor actuator 62F is constructed as a hydraulic smart cylinder having an integrated extension sensor 64F, this allows precise monitoring and control of the extension of the height of the front stringline sensor 60F.

<FIG> is a schematic illustration similar to <FIG> but showing the front sensor actuator 62F as a rotary spindle. The front sensor actuator position sensor 64F is shown as a rotary counter or angle sensor which counts the rotations of the spindle corresponding to a change in vertical position of the front stringline sensor 60F. The sensor actuator 62F of <FIG> includes a spindle <NUM> driven by a rotary motor <NUM>, which may be either a hydraulic motor or an electric motor <NUM>. The spindle <NUM> is supported by a spindle housing <NUM> supported from machine frame <NUM>. A nut <NUM> is threadedly received about spindle <NUM> and is vertically movable relative to machine frame <NUM> as guided by guide <NUM>. The front stringline sensor 60F is mounted on nut <NUM>. When the spindle <NUM> is rotated by motor <NUM> the nut <NUM> and attached sensor 60F is moved vertically up or down depending on the direction of rotation of the spindle <NUM>. The rotary counter 64F counts the rotations of the spindle <NUM> and generates a signal corresponding to the movement of the front stringline sensor 60F.

As will be understood by those skilled in the art, the stringline sensors 60F and 60R may be hydraulic sensors such that movement of wand <NUM> moves a hydraulic valve and directs flow of hydraulic fluid to the associated lifting column actuator <NUM>. Or the stringline sensors 60F and 60R may be electronic sensors that generate electrical signals to be used by a controller to generate command signals to various electromechanical actuators.

As previously noted, the many of the actuators disclosed herein may be "smart" hydraulic cylinders having integral extension sensors associated therewith.

A representative construction of such a "smart" hydraulic cylinder is shown in <FIG>, and the details of a "smart" hydraulic sensor actuator 62F will be described by way of example. <FIG> may also be representative of the internal construction of any of the other actuators herein described when those actuators are implemented as "smart" cylinders. In the illustrated embodiment, the actuator 62F includes an integrated sensor 64F configured to provide a signal corresponding to an extension of a piston portion <NUM> relative to a cylinder member <NUM> of the actuator 62F.

The sensor 64F includes a position sensor electronics housing <NUM> and a position sensor coil element <NUM>. The piston portion <NUM> of actuator 62F includes a piston <NUM> and a rod <NUM>. The piston <NUM> and rod <NUM> have a bore <NUM> defined therein, within which is received the position sensor coil element <NUM>.

The actuator 62F is constructed such that a signal is provided at connector <NUM> representative of the position of the piston <NUM> relative to the position sensor coil element <NUM>.

Such smart cylinders may operate on several different physical principles. Examples of such smart cylinders include but are not limited to magneto-strictive sensing, magneto-resistive sensing, resistive (potentiometric) sensing, Hall effect sensing, sensing using linear variable differential transformers, and sensing using linear variable inductance transducers.

As schematically illustrated in <FIG>, the machine <NUM> includes a control system <NUM> including a controller <NUM>. The controller <NUM> may be part of the machine control system of the slip form paver <NUM>, or it may be a separate control module. The controller <NUM> may for example be mounted in a control panel located at the operator's station <NUM>. The controller <NUM> is configured to receive input signals from the various sensors. The signals transmitted from the various sensors to the controller <NUM> are schematically indicated in <FIG> by lines connecting the sensors to the controller with an arrowhead indicating the flow of the signal from the sensor to the controller <NUM>.

For example, extension signals from the extension sensors 48F and 48R of the lifting column actuator cylinders 46F and 46R will be received by controller <NUM> so that the controller can monitor and control the extension of the lifting columns 32F and 32R. Extension signals from the sensor actuator position sensors 64F and 64R will be received by the controller <NUM> so that the controller <NUM> can monitor and control the vertical positions of the front and rear stringline sensors 60F and 60R. Extension signals from the extension sensor <NUM> of gate actuator <NUM> will be received by controller <NUM> so that the controller can monitor and control the extension of the gate actuator <NUM> and thus the height of gate <NUM>.

Similarly, the controller <NUM> will generate control signals for controlling the operation of the various actuators discussed above, which control signals are indicated schematically in <FIG> by lines connecting the controller <NUM> to graphic depictions of the various actuators with the arrow indicating the flow of the command signal from the controller <NUM> to the respective actuators. It will be understood that for control of a hydraulic cylinder type actuator the controller <NUM> will send an electrical signal to an electro/mechanical control valve (not shown) which controls flow of hydraulic fluid to and from the hydraulic cylinder.

In <FIG>, for ease of illustration, only the actuators for the left hand side of the machine <NUM> are shown, it being understood that the actuators for the right hand side of the machine <NUM> may be identical to those of the left hand side. Thus <FIG> schematically shows the adjustable left front sensor actuator 62F, the left front lifting column actuator 46F, a left side gate actuator <NUM>, the left rear sensor actuator 62R and the left rear lifting column actuator 46R.

It will be understood that when adjusting the longitudinal inclination <NUM> typically both the left and right front sensor actuators will be adjusted in an identical manner and both the left and right rear sensor actuators will be adjusted in an identical manner. But it will also be understood that if it is desired to create a cross-slope of the machine frame <NUM> the left and right sensor actuators may be adjusted differently from each other, and the front and rear sensor actuators of one and the same side may be adjusted in an identical manner.

Controller <NUM> includes or may be associated with a processor <NUM>, a computer readable medium <NUM>, a data base <NUM> and an input/output module or control panel <NUM> having a display <NUM>. An input/output device <NUM>, such as a keyboard, joystick or other user interface, is provided so that the human operator may input instructions to the controller. It is understood that the controller <NUM> described herein may be a single controller having all of the described functionality, or it may include multiple controllers wherein the described functionality is distributed among the multiple controllers.

Various operations, steps or algorithms as described in connection with the controller <NUM> can be embodied directly in hardware, in a computer program product <NUM> such as a software module executed by the processor <NUM>, or in a combination of the two. The computer program product <NUM> can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, or any other form of computer-readable medium <NUM> known in the art. An exemplary computer-readable medium <NUM> can be coupled to the processor <NUM> such that the processor can read information from, and write information to, the memory/ storage medium. In the alternative, the medium can be integral to the processor. The processor and the medium can reside in an application specific integrated circuit (ASIC). The ASIC can reside in a user terminal. In the alternative, the processor and the medium can reside as discrete components in a user terminal.

The term "processor" as used herein may refer to at least general-purpose or specific-purpose processing devices and/or logic as may be understood by one of skill in the art, including but not limited to a microprocessor, a microcontroller, a state machine, and the like. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The data storage in computer readable medium <NUM> and/or database <NUM> may in certain embodiments include a database service, cloud databases, or the like. In various embodiments, the computing network may comprise a cloud server, and may in some implementations be part of a cloud application wherein various functions as disclosed herein are distributed in nature between the computing network and other distributed computing devices. Any or all of the distributed computing devices may be implemented as at least one of an onboard vehicle controller, a server device, a desktop computer, a laptop computer, a smart phone, or any other electronic device capable of executing instructions. A processor (such as a microprocessor) of the devices may be a generic hardware processor, a special-purpose hardware processor, or a combination thereof.

Particularly the controller <NUM> may be programmed to receive extension signals from each of the extension sensors of the various hydraulic smart cylinders and to send control signals to control the extension of those hydraulic smart cylinders at least in part in response to the respective extension signals.

As is further described below with regard to various operational modes of the paving machine <NUM> that may be implemented by the control system <NUM>, it is sometimes desirable to adjust the longitudinal inclination of the paving machine <NUM> to affect the flow of concrete material at locations 16A, 16B, 16C, 16D as the paving machine <NUM> moves over the concrete material to form the concrete slab <NUM>.

The controller <NUM> will implement desired changes in longitudinal inclination of the machine frame <NUM> relative to ground surface <NUM> by sending command signals to the front and rear sensor actuators 62F and 62R to cause an adjustment in the longitudinal inclination of the machine frame <NUM>. The longitudinal inclination of machine frame <NUM> is schematically represented in <FIG> as the angle <NUM>. The angle <NUM> may be determined by the controller <NUM> based for example upon measured extension of the front and rear lifting columns which will establish the longitudinal inclination relative to a reference such as the ground surface or the string line reference.

This adjustment of the longitudinal inclination may be effected as follows. Adjustment of the vertical positions of the front and/or rear stringline sensors 60F and 60R by the front and rear sensor actuators 62F and 62R will in turn generate control signals from the front and/or rear stringline sensors 60F and 60R based upon which the grade control system will cause adjustment in the extension of the corresponding lifting column actuators 46F and 46R to bring the wand <NUM> of each of the stringline sensors 60F and 60R back to its "zero" position. Thus, for example, if it is desired to raise the front of the machine frame <NUM> relative to the rear of the machine frame <NUM> the controller <NUM> may send a command signal to the front sensor actuator 62F to extend actuator 62F. This will cause the wand <NUM> of sensor 60F to deflect upward as it maintains contact with stringline <NUM>, thus generating a control signal which will cause the front lifting column actuator 46F to extend until the wand <NUM> of the front stringline sensor 60F deflects back to its "zero" position. As is further explained below the controller <NUM> may determine, based upon the geometry of the machine <NUM>, the appropriate adjustments in vertical position of the stringline sensors 60F and 60R to cause any desired change in longitudinal inclination <NUM> of the machine frame <NUM>.

For example, in addition to adjusting the angle of inclination <NUM> it may be desired to control a predetermined rotational axis about which the machine frame rotates as the longitudinal inclination changes so that a height of the upper surface <NUM> of the formed but not yet hardened concrete slab <NUM> at and behind the predetermined rotational axis is not changed. This can be accomplished by adjusting both the front and rear lifting columns. Preferably such control of both the front and rear lifting columns is done so that the adjustment of the front and rear lifting columns occurs simultaneously. But it is also possible to adjust both the front and rear lifting columns sequentially or in alternating steps so long as the adjustment of both the front and rear lifting columns is accomplished within a sufficiently short interval of time such that there is no significant discontinuity created in the paved surface <NUM>.

For example, in the embodiment shown in <FIG> including the oscillating beam <NUM> following the slip form mold <NUM> it is the back edge of the bottom of the oscillating beam <NUM> which determines the height of the upper surface <NUM> of slab <NUM>. Accordingly, when adjusting the longitudinal inclination <NUM> of the machine as shown in <FIG>, the predetermined rotational axis would be axis <NUM> extending perpendicular to the plane of the drawing of <FIG> along the back edge of the bottom of the oscillating beam <NUM>. On the other hand, if the oscillating beam <NUM> were omitted from the paving machine <NUM>, then it would be the back edge of the slip form mold <NUM> which determines the height of the upper surface <NUM> of slab <NUM>, so in that case when adjusting the longitudinal inclination <NUM> the predetermined rotational axis would be the axis <NUM> extending perpendicular to the plane of the drawing of <FIG> along the back edge of the bottom of the slip form mold <NUM>.

As noted, the controller <NUM> may be configured via appropriate programming to determine the appropriate adjustments in vertical position of the front and rear stringline sensors 60F and 60R to achieve a desired change in longitudinal inclination angle <NUM> and to cause that change to occur by rotation of the machine frame about a predetermined axis of rotation such as the axis <NUM> at the back edge of the oscillating beam <NUM> or the axis <NUM> at the back edge of the slip form mold <NUM>. This may be done by configuring the controller <NUM> to adjust the longitudinal inclination of the machine frame by adjusting a ratio of a vertical adjustment of the front stringline sensor 60F to a vertical adjustment of the rear stringline sensor 60R as a function of a ratio of a horizontal distance of the front stringline sensor 60F from the rotational axis to a horizontal distance of the rear stringline sensor 60F from the rotational axis.

For example, as shown in <FIG> the horizontal distance of the front stringline sensor 60F from the rotational axis <NUM> is shown as LF, and the horizontal distance of the rear stringline sensor 60F from the rotational axis <NUM> is shown as LR. For the relatively small angles of inclination involved in the operation of the paving machine <NUM> the ratio of the vertical adjustment of front sensor 60F to that of the rear sensor 60R is substantially the same as the ratio LF/LR. Also, the associated ratio of the vertical adjustment of the front lifting column actuator 46F to the rear lifting column actuator 46R is similarly determinable by knowing the respective horizontal distances of the lifting columns from the rotational axis. Thus, by knowing the distances LF and LR, the controller can determine the desired changes in vertical position of the stringline sensors 60F and 60R to accomplish a desired change in extension/retraction of the lifting column actuators 46F and 46R to achieve the desired change in longitudinal inclination <NUM> about the predetermined rotational axis <NUM>. It is noted that the changes in vertical position of the stringline sensors 60F and 60R may be in opposite directions, i.e. one up and one down, to accomplish the desired rotation about the predetermined rotational axis <NUM>.

A method of controlling the slip form paving machine <NUM> described above including the front and rear stringline sensors 60F and 60R and the front and rear sensor actuators 62F and 62R may include steps of:.

The method may further include receiving the position signals from the front and rear sensor actuator positions sensors 64F and 64R with the controller <NUM> and generating the command signal at least in part based on the position signals.

Step (b) may further include adjusting the longitudinal inclination <NUM> of the machine frame <NUM> by adjusting both the front and rear lifting columns 32F and 32R thereby tilting the machine frame <NUM> about a predetermined rotational axis, e.g. <NUM> or <NUM>, so that a height of the upper surface <NUM> of the formed not yet hardened concrete slab <NUM> behind the rotational axis is not changed.

And step (b) may further include adjusting the longitudinal inclination <NUM> of the machine frame <NUM> by adjusting both the front and rear lifting columns 32F and 32R simultaneously.

And step (b) may further include adjusting the longitudinal inclination <NUM> of the machine frame <NUM> by adjusting a ratio of a vertical adjustment of the front stringline sensor to a vertical adjustment of the rear stringline sensor as a function of a ratio of a horizontal distance LF of the front stringline sensor 60F from the rotational axis to a horizontal distance LR of the rear stringline sensor 60R from the rotational axis.

And if the machine further includes at least one machine operating parameter sensor, e.g. the swelling sensor <NUM> discussed below, configured to sense at least one machine operating parameter and to generate sensor signals corresponding to the at least one machine operating parameter, the method may further include receiving the sensor signals with the controller and generating the command signal based at least in part on the sensor signals from the at least one machine operating parameter sensor.

One phenomenon which must be dealt with when operating a slip form paver <NUM> is that of swelling of the concrete layer <NUM> in the area 16C behind the slip form paver mold <NUM>. In an embodiment of the machine <NUM> a swelling sensor <NUM> may be provided to detect a swelling of the formed not yet hardened concrete slab <NUM> relative to the machine frame <NUM> behind the slip form mold <NUM>. The swelling sensor <NUM> generates a swelling signal which is received by the controller <NUM>. The controller <NUM>, in response to the swelling signal, may generate a command signal to one or more of the actuators discussed above to adjust at least one operating parameter of the paving machine <NUM>. As is further described below the operating parameters may include the longitudinal inclination angle <NUM>, the travel speed or advance speed of the paving machine <NUM> during paving, the speed or frequency of vibration of vibrators <NUM> and the height of the concrete gate <NUM>.

In one embodiment as seen in <FIG> the swelling sensor <NUM> may be a contactless distance sensor such as an ultrasonic sensor or a laser sensor supported from the slip form paver mold <NUM> or from the machine frame <NUM> and directed toward the surface <NUM> of the concrete slab <NUM> behind of the slip form paver mold <NUM> to measure a vertical distance from a fixed location on the mold <NUM> or on the machine frame <NUM> to the surface <NUM>.

Although only a single swelling sensor <NUM> is shown in the schematic illustration, it will be understood that multiple swelling sensors <NUM> may be placed across the width of the slip form paver machine <NUM>. As schematically shown in <FIG>, preferably the swelling sensor <NUM> includes at least two, and more preferably at least three, height sensors 220A, 220B, 220C spaced across a width <NUM> of the machine frame <NUM> and/or of the slab <NUM>. The concrete swelling may not be uniform across the width of the concrete slab and thus it may be desirable to make variable adjustments in operating parameters across the width of the concrete slab. Also, it will be understood that in rare cases the "swelling" of the concrete slab may even be negative, that is the concrete slab may shrink, and that also can be accommodated by the systems described above.

In another embodiment as schematically indicated in the plan view of <FIG>, the swelling sensor <NUM> may include at least one scanning sensor <NUM>, for example a laser scanner, configured to scan the height of the formed not yet hardened concrete slab <NUM> behind the slip form mold <NUM> across a continuous portion <NUM> of the width <NUM> of the machine frame <NUM>. A variety of sensor technologies may be used for the swelling sensor <NUM> and the other sensors disclosed herein. The improvements as disclosed herein do not depend on any specific sensor technology for measuring the distances identified. As previously noted, ultrasonic sensors may be used for spot measurement. LED or laser sensors could also be used for a spot measurement. With regard to scanning sensors a laser scanner may be used. Other scanning sensors could include a PMD camera or a LIDAR system.

It will be appreciated that the swelling of the concrete slab <NUM> in the area 16C may vary over a relatively short interval of time and thus it may be preferable to determine the height of the upper surface <NUM> in the area 16C as an average height over an interval of time so that adjustments are not made in response to short lived events. For example, an average height may be determined over a time interval in the range of from about <NUM> to about <NUM> seconds, optionally in a range of from about <NUM> to <NUM> seconds, still further optionally in a range of from about <NUM> to <NUM> seconds.

It will also be appreciated that the swelling of the concrete slab may be attributable to many different factors, some of which are relatively short term factors and some of which are relatively long term factors.

In the category of relatively short term factors, for example, there may be a load of concrete material dumped by a truck at location 16A which differs substantially from the previous material which had been supplied. The material supply typically is provided by a fleet of concrete mixer trucks bringing the material from a common source, but sometimes due to uncontrollable events, or a mistake or a delay in delivery, a load of concrete material may be dumped which is too wet or dry. Other short term events might include a change in the advance speed of the paving machine <NUM>.

In the category of relatively long term factors, a change in inclination angle <NUM> will correspondingly change the angle of the bottom of the slip form mold <NUM>. If the angle <NUM> is increased, thus raising the front edge of the mold <NUM> relative to the rear edge, this increases the amount of concrete "flowing" under the mold as the mold advances, thus increasing swelling at location 16C.

Similarly, if the gate <NUM> is raised this raises the height of the concrete in the area 16B just in front of the mold <NUM>, which will also lead to an increase in swelling in the area 16C behind the mold.

Changes in swelling in the area 16C tend to occur rather slowly. The controller <NUM> may be configured to recognize certain likely patterns of change in the swelling and to predict a height of the formed not yet hardened concrete slab behind the slip form mold <NUM> in the area 16C based at least in part upon a rate of change of the swelling sensor signal from the swelling sensor <NUM>.

It will be understood that in a typical paving operation the ultimate goal is consistency of the operation so that a favorable paving result can be set up and maintained throughout a paving job. Thus the "desired" swelling during a particular job may be to maintain a degree of swelling at a consistent level to that which exists when the paving machine is first set up for the job.

The controller <NUM> may also be configured to generate command signals to adjust various ones of the operating parameters automatically in response to measured or predicted swelling at location 16C, so as to correct for undesired swelling. The controller <NUM> may send a command signal to the advance drive of the paving machine <NUM> to increase or decrease the advance speed so as to reduce or increase, respectively, the swelling at area 16C. The controller <NUM> may send a command signal to the vibrators <NUM> to increase or decrease the vibrator speed so as to increase or reduce, respectively, the swelling at area 16C. The controller <NUM> may send a command signal to the gate actuator <NUM> to raise or lower the gate <NUM> to increase or reduce, respectively, the swelling at area 16C.

And as discussed above, the controller <NUM> may send command signals to the front and rear stringline sensor actuators 62F and 62R to increase or decrease the longitudinal inclination angle <NUM> to increase or reduce, respectively, the swelling at area 16C.

Because it may be difficult to determine what is the primary cause of an observed change in swelling, the controller <NUM> may be configured to adjust the various effective machine operating parameters in an order of the ease of implementation, or the speed of implementation. For example, the controller <NUM> may be configured to respond to an observed increase in swelling by adjusting the various machine parameters in the following order, to the extent that the selected parameter is not already at a maximum or minimum value:.

A method of operating the slip form paving machine <NUM> described above including the swelling sensor <NUM> may include steps of:.

Step (a) may further include monitoring swelling of the formed not yet hardened concrete slab behind the slip form mold <NUM> as an average swelling over an interval of time.

Step (a) may further include monitoring the swelling of the formed not yet hardened concrete slab <NUM> behind the slip form mold <NUM> in at least two, and preferably at least three locations across the width <NUM> of the paving machine <NUM>.

The at least one operating parameter adjusted in step (c) may include a travel speed of the paving machine <NUM>, a vibrator speed or frequency of the vibrator <NUM> located in front of the slip form mold <NUM>, a concrete supply gate <NUM> height in front of the slip form mold <NUM> or the longitudinal inclination <NUM> of the machine <NUM>.

Step (c) may further include lowering the front end of the machine frame <NUM> relative to the rear end to decrease the swelling of the formed not yet hardened concrete slab <NUM> behind the slip form mold <NUM> in the area 16C, and raising the front end of the machine frame <NUM> relative to the rear end to increase the swelling of the formed not yet hardened concrete slab behind the slip form mold <NUM>.

And when the paving machine <NUM> includes the oscillating beam <NUM>, step (c) may further include adjusting the longitudinal inclination <NUM> of the machine frame <NUM> by adjusting both the front and rear lifting columns 32F and 32R and thereby tilting the machine frame <NUM> about a rotational axis <NUM> adjacent a rear edge of the oscillating beam <NUM> so that a height of the upper surface <NUM> of the formed not yet hardened concrete slab <NUM> behind the oscillating beam <NUM> is not changed. And step (c) may further include adjusting the longitudinal inclination <NUM> of the machine frame <NUM> by adjusting both the front and rear lifting columns 32F and 32R simultaneously.

When the paving machine <NUM> does not include an oscillating beam <NUM>, step (c) may further include adjusting the longitudinal inclination <NUM> of the machine frame <NUM> by adjusting both the front and rear lifting columns 32F and 32R and thereby tilting the machine frame <NUM> about a rotational axis <NUM> adjacent a rear edge of the slip form mold <NUM> so that a height of the upper surface <NUM> of the formed not yet hardened concrete slab <NUM> behind the slip form mold <NUM> is not changed. And step (c) may further include adjusting the longitudinal inclination of the machine frame by adjusting both the front and rear lifting columns simultaneously.

The method may include after step (c) repeating steps (a) and (b) after a lag time interval sufficient to allow the adjusting of step (c) to result in a change in the swelling of the formed not yet hardened concrete slab <NUM> behind the slip form mold <NUM>, and further adjusting the longitudinal inclination <NUM> of the machine frame <NUM> in a direction to counteract any further determined current or predicted deviation of the swelling of the formed not yet hardened concrete slab <NUM> behind the slip form mold <NUM>. The lag time interval may be based on a time necessary for the paving machine <NUM> to travel a specified distance in the paving direction <NUM>. For example, the lag time may be a time sufficient for the paving machine <NUM> to advance a distance in a range of from <NUM> to <NUM>, optionally in a range of from about <NUM> to <NUM>, and further optionally in a range of from about <NUM> to <NUM>.

Another phenomenon encountered in slip form paving when using an oscillating beam such as the oscillating beam <NUM> is the formation of the "roll" 16D of not yet hardened concrete material immediately in front of the oscillating beam <NUM>. The roll 16D tends to curl forward away from the oscillating beam and is generally in the form of a somewhat irregular shaped roughly cylindrical roll of not yet hardened concrete material. The material in the roll is in movement and the roll grows and shrinks in its cross-sectional size, and particularly in its height, depending on various operational parameters of the paving machine <NUM>. Maintaining the roll 16D at an appropriate size is important to proper functioning of the oscillating beam <NUM>.

One machine parameter which affects the size of the roll 16D is the longitudinal inclination <NUM> of the machine frame <NUM>. Keep in mind that when using an oscillating beam <NUM> any changes in inclination are preferably made by rotating the machine frame about rotational axis <NUM> at the rear edge of the oscillating beam <NUM> so that the finish height of the upper surface <NUM> of the slab <NUM> is not changed. If the longitudinal inclination <NUM> is increased this will allow more concrete material to pass under the slip form mold <NUM> and build up ahead of the oscillating beam <NUM>. Conversely, decreasing the angle of longitudinal inclination <NUM> will reduce the amount of concrete material passing under the advancing slip form mold <NUM> and thus reduce the size of the roll 16D.

The size of the roll 16D may be monitored with a roll size sensor <NUM> configured to detect a size of the roll 16D in front of the oscillating beam <NUM>. The roll size sensor <NUM> may be configured to detect a parameter corresponding to a cross-sectional dimension of the roll 16D. It will be understood that the roll 16D is irregularly shaped and when a cross-sectional dimension such as height or width is discussed below, such a dimension is an irregular perhaps constantly changing dimension. A parameter "corresponding to" such a dimension need not be an exact quantitative measure of an actual dimension, but it is just somehow approximately representative of such a dimension.

In one embodiment schematically shown in <FIG> the roll size sensor <NUM> is a roll height sensor <NUM> and the parameter is a vertical distance <NUM> from the sensor <NUM> to a top of the roll 16D. Since the vertical distance from the sensor <NUM> to the bottom of the oscillating beam <NUM> is known, subtraction of the distance <NUM> gives the height <NUM> of roll 16D.

In a second embodiment also schematically shown in <FIG> the roll size sensor is a roll width sensor 230W and the parameter is a horizontal distance <NUM> from the sensor 230W to the side of the roll 16D. Since the horizontal distance from the sensor 230W to the front of the oscillating beam <NUM> is known, subtraction of the distance <NUM> gives the width <NUM> of the roll 16D.

In one embodiment as seen in <FIG> the roll size sensors <NUM> and 230W may each be a contactless distance sensor such as an ultrasonic sensor or a laser sensor. Although only a single roll size sensor <NUM> or 230W is shown in the schematic illustration, it will be understood that multiple roll size sensors <NUM> may be placed across the width <NUM> of the slip form paver machine <NUM> in a manner similar to that described with regard to <FIG>. Preferably each roll size sensor <NUM> or 230W includes at least two, and more preferably at least three, discrete sensors paced across the width <NUM> of the machine frame <NUM>. The size and shape of the roll 16D may not be uniform across the width of the concrete slab and thus it may be desirable to make variable adjustments in operating parameters across the width of the concrete slab.

In another embodiment analogous to that of <FIG> for the swelling sensor, the roll size sensor <NUM> or 230W may include at least one scanning sensor, for example a laser scanner, configured to scan the height or width of the roll 16D across a continuous portion <NUM> of the width <NUM> of the machine frame <NUM>. As noted above any suitable sensor technology may be used for the roll control sensors <NUM> or 230W.

The controller <NUM> may be configured to receive sensor signals from the roll size sensor <NUM> and/or 230W and to generate a command signal to one or both of the sensor actuators 60F and 60R to adjust the longitudinal inclination <NUM> of the machine <NUM>.

If the paving machine <NUM> is configured to use a grade control system other than a stringline type grade control system, e.g. the satellite based system <NUM>, <NUM>, <NUM> or the Total Station type system <NUM>, <NUM>, <NUM>, then in the absence of the sensor actuators <NUM> the controller <NUM> could send command signals directly to the hydraulic actuators 46F and 46R of the lifting columns 32F and 32R.

It will be appreciated that the exterior shape of the roll 16D may be somewhat irregular and thus it may be preferable for the controller <NUM> to be configured to determine the height or width of the roll 16D as an average height or width over an interval of time so that adjustments are not made in response to short lived events. For example, an average height or width may be determined over a time interval in the range of from about <NUM> to <NUM> minutes; optionally in a range of from about <NUM> to <NUM> minutes; and further optionally in a range of from about <NUM> to <NUM> minutes.

The controller <NUM> may further be configured to predict the size of the roll 16D based at least in part upon a rate of change of the sensor signals from the roll size sensors <NUM> and/or 230W.

The controller <NUM> may further be configured to lower the front end of the machine frame <NUM> to decrease the size of the roll 16D and to raise the front end of the machine frame <NUM> relative to the rear end to increase the size of the roll 16D.

The controller <NUM> may be further configured to adjust the longitudinal inclination <NUM> of the machine frame <NUM> by adjusting both the front and rear lifting columns 32F and 32R simultaneously thereby tilting the machine frame <NUM> about the rotational axis <NUM> adjacent the rear edge of the oscillating beam <NUM> so that the height of the upper surface <NUM> of the formed not yet hardened concrete slab <NUM> behind the oscillating beam <NUM> is not changed.

For any given paving machine <NUM> and set of operating parameters of the machine and the concrete material, a desired size of the roll 16D will typically be known, sometimes as a range of sizes. The controller may be configured to: (a) monitor the sensor signals from the roll size sensors <NUM> and/or 230W; (b) based at least in part on the sensor signals determine a current or a predicted deviation of the size of the roll 16D from the desired size; and (c) generate a command signal to adjust the longitudinal inclination of the machine frame in a direction to counteract the deviation.

After step (c) the controller <NUM> may repeat steps (a) and (b) after a lag time interval sufficient to allow the adjusting of step (c) to result in a change in the size of the roll 16D. Then the controller <NUM> may further adjust the longitudinal inclination of the machine frame <NUM> in a direction to counteract any further determined current or predicted deviation of the size of the roll 16D. The lag time interval may be based on a time necessary for the paving machine <NUM> to travel a specified distance in the paving direction.

Other machine operating parameters, other than the longitudinal inclination <NUM>, may affect the size of the roll 16D. One such other operating parameter is the height of the mass of concrete material in front of the slip form mold <NUM> in the area 16B. This height may be detected by a concrete supply height sensor <NUM>. Like the swelling sensor <NUM> and the roll height sensor <NUM>, the concrete supply height sensor <NUM> may be either an ultrasonic sensor, preferably at least two and more preferably at least three such sensors across the width of the slab <NUM>, or a scanning sensor such as a laser scanner.

Another such operating parameter is the slab swelling in the area 16C as detected by the swelling sensor <NUM>.

The controller <NUM> may monitor the signals from the concrete supply height sensor <NUM> and/or the swelling sensor <NUM> and generate its command signal to adjust the longitudinal inclination <NUM> at least in part on those signals and predicted impacts of those parameters on the roll size.

The paving machine <NUM> may be further configured to allow monitoring and/or control of the thickness of the paved slab <NUM>. To this end the paving machine <NUM> may include front and rear height sensors <NUM> and <NUM>.

The front height sensor <NUM> may be configured to detect a distance <NUM> relative to the machine frame <NUM> from the ground surface <NUM> ahead of the concrete slab <NUM>, and to generate a front height signal. The front height sensor <NUM> may be arranged forward of the front lifting columns 32F, but it may be at any suitable location above the ground surface <NUM> ahead of the expected placement of the mass of unformed concrete material 16A.

The rear height sensor <NUM> may be configured to detect a distance <NUM> relative to the machine frame <NUM> from the upper surface <NUM> of the formed concrete slab <NUM> and to generate a rear height signal. The rear height sensor <NUM> may be arranged rearward of the rear lifting columns 32R, but it may be at any suitable location behind the oscillating beam <NUM>.

The controller <NUM> may be configured to receive the front and rear height signals from front and rear height sensors <NUM> and <NUM> and to determine a thickness <NUM> of the concrete slab <NUM> based at least in part on the front and rear height signals.

The front and/or rear height sensors <NUM> and/or <NUM> may each be an ultrasonic sensor. Preferably each such front and/or rear height sensor includes at least two, and more preferably at least three, discrete ultrasonic sensors spaced across the width <NUM> of slab <NUM> in a manner analogous to that shown in <FIG> for the swelling sensors.

In another embodiment the front and/or rear height sensors <NUM> and <NUM> may each include at least one scanning sensor, for example a scanning laser sensor, configured to scan the ground surface <NUM> and/or the slab surface <NUM> across a continuous portion <NUM> of the width <NUM> of the slab analogous to that shown in <FIG> for the swelling sensors. The at least one scanning sensor may include two or more scanning sensors scanning different or overlapping continuous portions of the width <NUM> of the slab.

To determine the thickness <NUM> of the slab <NUM> at any given location on the ground surface <NUM> the controller <NUM> may be configured to compare the front height signal corresponding to the given location on the ground surface <NUM> to a later occurring rear height signal corresponding to substantially the same given location on the ground surface. This may be accomplished in various ways.

In one aspect the controller <NUM> may be configured to correlate the front and rear height signals based upon the machine <NUM> traveling a horizontal distance substantially equal to a horizontal spacing <NUM> between the front and rear height sensors <NUM> and <NUM>.

In another aspect the controller <NUM> may be configured to store data corresponding to the height signals in the computer memory <NUM> and correlate the data to a location of the machine <NUM> upon the ground surface <NUM>. If the machine <NUM> is using a stringline grade control system like one of those schematically shown in <FIG> this correlation may be performed by associating each height signal with a distance the machine <NUM> has traveled along the stringline <NUM> from a starting location. This distance sensing may be done by a pick-up or sensor in the track drives to determine the traveled distance of the paver along the track.

If the machine <NUM> is using a three-dimensional grade control system based upon a position of the machine <NUM> in a reference system external to the machine <NUM>, such as is the case when using a satellite based grade control system <NUM>, <NUM>, <NUM> or a Total station type grade control system <NUM>, <NUM>, <NUM>, the controller <NUM> may be configured to correlate the height data to the position of the machine <NUM> in the reference system external to the machine <NUM>. For example, the controller <NUM> may be configured to correlate the height data to the position of the machine <NUM> according to GPS or GNSS satellite system coordinates.

For any of the above techniques, when the present disclosure refers to "substantially" the same location, or to a distance "substantially" equal to the horizontal spacing between sensors, it will be understood that the location or the distance need not be exactly the same. For one thing, depending upon the particular type of sensors used, the location on the ground surface or on the upper surface of the slab which is seen by the sensor is not a mathematical point, but instead is an area. It will also be understood that any sensor such as <NUM> or <NUM> will have a focal point in the center of that area, or for a scanning sensor as shown in <FIG> there will be a focal line across the width of the slab. Furthermore, given the expected general uniformity of the ground surface and of the upper surface <NUM> of the slab <NUM>, some variation in the focal point of the front and rear sensors <NUM> and <NUM> may be permitted without adversely affecting the comparison to determine the thickness <NUM> of the slab. Thus, as used in the present disclosure, the phrase "substantially the same location" shall be understood to include a focal point or focal line of the rear sensor <NUM> that is within <NUM> of the focal point or focal line of the front sensor <NUM>. Similarly, a distance "substantially" equal to the horizontal spacing between sensors <NUM> and <NUM> will be understood to include any distance that is within plus or minus <NUM> of the horizontal spacing between the focal points of the front and rear sensors.

The controller <NUM> may be further configured to determine the total volume of a concrete slab <NUM> formed during a paving operation and optionally to generate reports of the same. This volume can be determined by integrating the thickness <NUM> of the concrete slab over the area of the slab as determined by its length in the paving direction <NUM> and its width <NUM>. Such a a report may for example be used for billing purposes and to show performance of contract specifications. Such reports may also be representative of other performance parameters, such as minimum thickness, maximum thickness, or to otherwise document the paving thickness <NUM> as a function of geographic location on the slab <NUM>.

Additionally, the controller <NUM> may be configured to control the paving thickness <NUM>. The controller <NUM> may be configured to send command signals to the lifting columns 32F and 32R, or to the front and rear sensor actuators 62F and 62R, to automatically adjust the height of the machine frame relative to the ground surface <NUM> and thereby control the thickness of the concrete slab <NUM> based at least in part on a comparison of a determined thickness <NUM> of the slab <NUM> to a desired thickness of the slab at a given geographic location. In either case the command signals cause the lifting columns to adjust the height of the machine frame relative to the ground surface to control the thickness of the concrete slab.

Such a method may be described as including steps of:.

The determining step may include comparing a front height signal corresponding to a given location on the ground surface <NUM> to a later occurring rear height signal corresponding to substantially the same given location on the ground surface. As described above this may be done by correlating the front and rear height signals based upon the machine <NUM> traveling a horizontal distance substantially equal to horizontal spacing <NUM> between the front and rear height signals.

The method may further include storing data corresponding to the height signals in the computer memory <NUM> and correlating the data to a location of the machine <NUM> upon the ground surface <NUM>.

The method may further include a step of automatically generating with the controller <NUM> a report representative of a total volume of the concrete slab <NUM> formed during a paving operation.

The method may further include steps of:.

Claim 1:
: A slip form paving machine, comprising:
a machine frame (<NUM>);
a plurality of ground engaging wheels or tracks (<NUM>);
front and rear height adjustable lifting columns (<NUM>) supporting the machine frame (<NUM>) from the ground engaging wheels or tracks (<NUM>), the lifting columns (<NUM>) being adjustable to adjust a longitudinal inclination of the machine frame in a paving direction (<NUM>);
a slip form mold (<NUM>) supported from the machine frame (<NUM>) for molding a mass of concrete into a formed not yet hardened concrete slab as the paving machine moves forward in the paving direction (<NUM>);
an oscillating beam (<NUM>) supported from the machine frame (<NUM>) behind the slip form mold (<NUM>) for engaging and oscillating transversely to the paving direction (<NUM>) upon an upper surface of the formed not yet hardened concrete slab to smooth the upper surface;
characterized in that the slip form paving machine comprises a roll size sensor (<NUM>) configured to detect a size of a roll of not yet hardened concrete created in front of the oscillating beam (<NUM>).