Some embodiments of a ground surface treatment system can include a flexible roller system having one or more of rollers arranged in a side-by-side position and include a flexible axle member extending through each row of rollers.

An agricultural system includes an agricultural row unit movable on a field between a first soil condition and a second soil condition, the first soil condition having a different soil hardness than the second soil condition. A down-pressure actuator applies an initial first pressure associated with the first soil condition. A soil-hardness sensing device is positioned at a distance D forward of the row unit and outputs a soil-hardness change signal when detecting a change from the first soil condition to the second soil condition. At least one memory device stores instructions that, when executed by at least one processor, cause the down-pressure actuator to change, in response to receiving the soil-hardness change signal, the initial first pressure to a different second pressure when the row unit encounters the second soil condition.

The disclosure describes, in one aspect, a system and method for controlling a rotation angle of a blade of a motor grader having a front frame operatively coupled to a rear frame at a point defining an articulation angle between the front and rear frames. The control system includes at least one sensor operatively associated with the blade, at least one sensor operatively associated with a wheel, at least one sensor operatively associated with at least one of the front frame or the rear frame, and a controller operatively coupled to the at least one sensors. The controller is adapted to determine a current position of the blade, determine a wheel steering angle, determine an articulation angle, and control the rotation angle of the blade based in part on the wheel steering angle and the articulation angle.

A cleanup device having a first board having a first edge, a second board having a first edge, a first hinge attached to the first edge of the first board and the first edge of the second board, an aperture defined by a portion of the first edge of the first board and a portion of the first edge of the second board, a first plate slidably attached to the first board, wherein the first plate is movable from a first, open position where the aperture is open to a second, closed position where the first plate extends over at least a portion of the aperture, and wherein a top surface of the first board is movable towards a top surface of the second board to form a V-shaped surface for directing dirt or soil off of the first board and the second board.

A front loader (10) for a tractor with a parking stand unit (28) including a parking support (30) pivotably mounted on the front loader arm (12). A locking brace (32) is pivotably seated at one end on the parking support (30) and is movably guided at the other end by a guidance means (50) formed on the locking brace (32) and at least one guide groove (48, 49) formed in the parking support (30). The guidance means (50) can be brought by pivoting the parking support (30) into the parking position (P3) into a locking position in which it comes to rest at a stop (66) formed in the guide groove (48, 49). The guidance means (50) can be pressed against the stop (66) and fixed in the locking position by a support force of the front loader arm (12) acting in the parking position (P3) on the locking brace (32).

A hand held material moving tool is disclosed. The material engaging implement has a material engaging portion adapted for movement of material. A handle is connected to a top surface of the tool. The handle is positioned low and in close proximity to the material engaging portion of the implement. The handle is connected to the tool by a swivel mechanism permitting a predetermined amount of pivot of the implement in relation to the handle about an axis.

A swing control apparatus and a swing control method for a construction machine are provided. The swing control apparatus includes a start position estimation unit, a stop target position calculation unit, and a swing motor position control unit. Even if an operator releases a lever or commands a stop at different times, an upper swing structure of the construction machine (for example, excavator) can be stopped within a predetermined range, and thus the inconvenience caused by an additional driving operation, which is required as the stop position differs according to the time point where the stop command starts, can be solved.

A turf cutter device, an infill extractor/collector device, and a turf wind-up device are used to facilitate the cost-effective removal of an infilled synthetic turf and the subsequent installation of a new turf at the same site, with minimal subsurface disruption. An infill extractor/collector device mounted on a motorized vehicle moves a relatively narrow strip of filled artificial turf from the surface, in front of the vehicle, and directs the strip to an infill removal station. The infill removal station inverts the strip and redirects the strip back toward the front of the vehicle, after agitating the strip to extract the infill. After redirecting the strip toward the front of the vehicle, the vehicle drives over the unfilled strip. Meanwhile, the extractor/collector device moves the extracted infill rearwardly to a bag located in a trailer. The turf cutter device is used prior to infill extraction, while the turf wind up device may be used before or after infill extraction, depending on whether infill extraction takes place at the field or at a remote site, respectively.

A system for determining a cut location at a work surface includes a position sensor and a controller. The controller stores a desired operating parameter and a final design plane of the work surface and determines an actual profile of the work surface. The controller determines a plurality of target profiles corresponding to different cut locations. The target profiles are based at least in part upon the cut location, a loading profile, slot parameters, and the actual profile of the work surface. The controller further determines an optimized target profile relative to the desired operating parameter and the optimized target profile defines an optimized cut location.

A brake control system and method for motor vehicles is provided with an electronic control unit, by which, when the motor vehicle is stationary, a parking brake function can be activated manually or automatically. Its deactivation occurs upon reaching a predefined release condition. In the presence of a release condition the brake pressure, which was built up for the parking brake function, is released in a time offset manner at least in relation to the axles of the vehicle by way of the control unit.

A hitch on a vehicle is raised and lowered by a hydraulic actuator controlled by an electrically operated valve. A control system receives a command that indicates a designated velocity and uses the command to operate the valve. Based on a reference external force exerted on the hitch, the control system is configured with relationships for converting a plurality of command values to corresponding electric current levels for operating the valve. The control system compensates for effects due to differences between the actual force acting on the hitch and the reference external force. Velocity feedback adjusts the electric current level applied to the valve. The passive load force control provides a predictor of the hitch load force to eliminate overshoot/undershoot of hitch motion. During hitch motion, the velocity feedback also compensates for effects due to load and hitch geometry changes that occur.

An apparatus for extracting and collecting particulate infill from an infilled artificial turf field. A vehicle has a first forward end and a second rearward end. An infill extractor is located at the first end of the vehicle and adapted to extract infill from a strip of infilled athletic turf. Extracted infill falls into a bottom section of the infill extractor. An infill mover is secured to the vehicle and adapted to move the extracted infill from the bottom section of the infill extractor toward the second end of the vehicle. An infill collector is connected to the second end of the vehicle and operable to cooperate with the infill mover to collect the moved infill. The infill collector includes a frame that is laterally movable relative to the vehicle from an operative “in use” position to a stowed position.

According to embodiments of the invention, a TFT array substrate, a manufacturing method of the TFT array substrate and a display device are provided. The method comprises: depositing a metal film on a substrate, and forming a gate electrode and a gate line; forming a gate insulating layer and a passivation layer on the substrate; depositing a transparent conductive layer, a first source/drain metal layer and a first ohmic contact layer, and forming a drain electrode, a pixel electrode, a data line, and a first ohmic contact layer pattern provided on the drain electrode; and depositing a semiconductor layer, a second ohmic contact layer and a second source/drain metal layer, and forming a source electrode, a second ohmic contact layer pattern provided below the source electrode, and a semiconductor channel between the source electrode and the drain electrode.

An organic light emitting display device includes a light shield layer formed on a substrate and a buffer layer formed on an entire surface of the substrate, an oxide semiconductor layer and first electrode formed on the buffer layer, a gate insulation film and gate electrode formed on the oxide semiconductor layer while being deposited to expose both edges of the oxide semiconductor layer, an interlayer insulation film formed to expose both the exposed edges of the oxide semiconductor layer and the first electrode, source and drain electrodes connected with one edge and the other edge of the oxide semiconductor layer, respectively, and a protective film formed to cover the source and drain electrodes while exposing a region of the first electrode so as to define a luminescent region and a non-luminescent region.

A display device includes a pixel portion including a plurality of pixels each including a first transistor, a second transistor, and a light-emitting element, in which a gate of the first transistor is electrically connected to a scan line, one of a source and a drain of the first transistor is electrically connected to a signal line, and the other of them is electrically connected to a gate of the second transistor; one of a source and a drain of the second transistor is electrically connected to a power supply line and the other of them is electrically connected to the light-emitting element, and the first transistor includes an oxide semiconductor layer. A period when the display device displays a still image includes a period in which output of a signal to all the scan lines in the pixel portion is stopped.

An organic light emitting diode (OLED) display a includes: a substrate; an organic light emitting element on the substrate and including a first electrode, a light emission layer, and a second electrode; and an encapsulation layer on the substrate while covering the organic light emitting element. The encapsulation layer includes an organic layer and an inorganic layer. A mixed area, where organic materials forming the organic layer and inorganic materials forming the inorganic layer co-exist along a plane direction of the encapsulation layer, is formed at the boundary between the organic layer and the inorganic layer.

The present invention relates to a film for flip chip type semiconductor back surface to be formed on a back surface of a semiconductor element flip chip-connected to an adherend, the film for flip chip type semiconductor back surface containing an inorganic filler in an amount within a range of 70% by weight to 95% by weight based on the whole of the film for flip chip type semiconductor back surface.

There is provided a substrate for light-emitting element, including a mounting surface on which a light-emitting element is to be mounted, the mounting surface being one of two opposed main surfaces of the substrate. The substrate of the present invention is provided with a protection element for the light-emitting element, the protection element comprising a voltage-dependent resistive layer embedded in a body of the substrate, and comprising a first electrode and a second electrode each of which is in connection with the voltage-dependent resistive layer wherein the light-emitting element is to be mounted such that it is positioned in an overlapping relation with the voltage-dependent resistive layer.

An object is to manufacture a semiconductor device with high reliability by providing the semiconductor device including an oxide semiconductor with stable electric characteristics. In a transistor including an oxide semiconductor layer, a gallium oxide film is used for a gate insulating layer and made in contact with an oxide semiconductor layer. Further, gallium oxide films are provided so as to sandwich the oxide semiconductor layer, whereby reliability is increased. Furthermore, the gate insulating layer may have a stacked structure of a gallium oxide film and a hafnium oxide film.

The band tail state and defects in the band gap are reduced as much as possible, whereby optical absorption of energy which is in the vicinity of the band gap or less than or equal to the band gap is reduced. In that case, not by merely optimizing conditions of manufacturing an oxide semiconductor film, but by making an oxide semiconductor to be a substantially intrinsic semiconductor or extremely close to an intrinsic semiconductor, defects on which irradiation light acts are reduced and the effect of light irradiation is reduced essentially. That is, even in the case where light with a wavelength of 350 nm is delivered at 1×1013 photons/cm2·sec, a channel region of a transistor is formed using an oxide semiconductor, in which the absolute value of the amount of the variation in the threshold voltage is less than or equal to 0.65 V.

A semiconductor device includes wiring layers formed over a semiconductor wafer, a via-layer between the wiring layers, conductive films in the wiring layers, and a via-plug in the via-layer connecting the conductive films of the wiring layers above and below, a scribe region at an outer periphery of a chip region along an edge of the semiconductor substrate and including a pad region in the vicinity of the edge, the pad region overlapping the conductive films of the plurality of wiring layers in the plan view, the plurality of wiring layers including first second wiring layers, the conductive film of the first wiring layer includes a first conductive pattern formed over an entire surface of said pad region in a plan view, and the conductive film of the second wiring layer includes a second conductive pattern formed in a part of the pad region in a plan view.

A light emitting device including a light emitting structure having a first conduction type semiconductor layer, an active layer, and a second conduction type semiconductor layer, a transparent conductive layer disposed on the light emitting structure, a metal filter having an irregular pattern disposed between the light emitting structure and the transparent conductive layer, and openings disposed between the irregular patterns in the metal filter.

An electronic device includes a silicon carbide layer including an n-type drift region therein, a contact forming a junction, such as a Schottky junction, with the drift region, and a p-type junction barrier region on the silicon carbide layer. The p-type junction barrier region includes a p-type polysilicon region forming a P-N heterojunction with the drift region, and the p-type junction barrier region is electrically connected to the contact. Related methods are also disclosed.

An object is to provide a semiconductor device including an oxide semiconductor film, which has stable electrical characteristics and high reliability. A stack of first and second material films is formed by forming the first material film (a film having a hexagonal crystal structure) having a thickness of 1 nm to 10 nm over an insulating surface and forming the second material film having a hexagonal crystal structure (a crystalline oxide semiconductor film) using the first material film as a nucleus. As the first material film, a material film having a wurtzite crystal structure (e.g., gallium nitride or aluminum nitride) or a material film having a corundum crystal structure (α-Al2O3, α-Ga2O3, In2O3, Ti2O3, V2O3, Cr2O3, or α-Fe2O3) is used.

A semiconductor device, includes a semiconductor substrate, a first interconnect layer formed over the semiconductor substrate, a gate electrode formed in the first interconnect layer, a gate insulating film formed over the gate electrode, a second interconnect layer formed over the gate insulating film, an oxide semiconductor layer formed in the second interconnect layer, and a via formed in the second interconnect layer and connected to the oxide semiconductor layer. The gate electrode, the gate insulating film and the oxide semiconductor layer overlap in a plan view.

Semiconductor devices including a stressor in a recess and methods of forming the semiconductor devices are provided. The methods may include forming a trench in an active region and the trench may include a notched portion of the active region. The methods may also include forming an embedded stressor in the trench. The embedded stressor may include a lower semiconductor layer and an upper semiconductor layer, which has a width narrower than a width of the lower semiconductor layer. A side of the upper semiconductor layer may not be aligned with a side of the lower semiconductor layer and an uppermost surface of the upper semiconductor layer may be higher than an uppermost surface of the active region.

It is an object to manufacture a highly reliable semiconductor device including a thin film transistor whose electric characteristics are stable. An insulating layer which covers an oxide semiconductor layer of the thin film transistor contains a boron element or an aluminum element. The insulating layer containing a boron element or an aluminum element is formed by a sputtering method using a silicon target or a silicon oxide target containing a boron element or an aluminum element. Alternatively, an insulating layer containing an antimony (Sb) element or a phosphorus (P) element instead of a boron element covers the oxide semiconductor layer of the thin film transistor.

A semiconductor device which includes a thin film transistor having an oxide semiconductor layer and excellent electrical characteristics is provided. Further, a method for manufacturing a semiconductor device in which plural kinds of thin film transistors of different structures are formed over one substrate to form plural kinds of circuits and in which the number of steps is not greatly increased is provided. After a metal thin film is formed over an insulating surface, an oxide semiconductor layer is formed thereover. Then, oxidation treatment such as heat treatment is performed to oxidize the metal thin film partly or entirely. Further, structures of thin film transistors are different between a circuit in which emphasis is placed on the speed of operation, such as a logic circuit, and a matrix circuit.

A light-emitting element includes a first electrode, a first light-emitting layer formed over the first electrode, a second light-emitting layer formed on and in contact with the first light-emitting layer to be in contact therewith, and a second electrode formed over the second light-emitting layer. The first light-emitting layer includes a first light-emitting substance and a hole-transporting organic compound, and the second light-emitting layer includes a second light-emitting substance and an electron-transporting organic compound. Substances are selected such that a difference in LUMO levels between the first light-emitting substance, the second light-emitting substance, and the electron-transporting organic compound is 0.2 eV or less, a difference in HOMO levels between the hole-transporting organic compound, the first light-emitting substance, and the second light-emitting substance is 0.2 eV or less, and a difference in LUMO levels between the hole-transporting organic compound and the first light-emitting substance is greater than 0.3 eV.

A semiconductor film having an impurity region to which at least an n-type or p-type impurity is added and a wiring are provided. The wiring includes a diffusion prevention film containing a conductive metal oxide, and a low resistance conductive film over the diffusion prevention film. In a contact portion between the wiring and the semiconductor film, the diffusion prevention film and the impurity region are in contact with each other. The diffusion prevention film is framed in such a manner that a conductive film is exposed to plasma generated from a mixed gas of an oxidizing gas and a halogen-based gas to form an oxide of a metal material contained in the conductive film, the conductive film in which the oxide of the metal material is formed is exposed to an atmosphere containing water to be fluidized, and the fluidized conductive film is solidified.

The silicon nitride layer 910 formed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH4) and ammonia (NH3) is provided on and in direct contact with the oxide semiconductor layer 905 used for the resistor 354, and the silicon nitride layer 910 is provided over the oxide semiconductor layer 906 used for the thin film transistor 355 with the silicon oxide layer 909 serving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layer 905 than into the oxide semiconductor layer 906. As a result, the resistance of the oxide semiconductor layer 905 used for the resistor 354 is made lower than that of the oxide semiconductor layer 906 used for the thin film transistor 355.

To provide a semiconductor device which has transistor characteristics with little variation and includes an oxide semiconductor. The semiconductor device includes an insulating film over a conductive film and an oxide semiconductor film over the insulating film. The oxide semiconductor film includes a first oxide semiconductor layer, a second oxide semiconductor layer over the first oxide semiconductor layer, and a third oxide semiconductor layer over the second oxide semiconductor layer. The energy level of a bottom of a conduction band of the second oxide semiconductor layer is lower than those of the first and third oxide semiconductor layers. An end portion of the second oxide semiconductor layer is positioned on an inner side than an end portion of the first oxide semiconductor layer.

It is an object to provide a highly reliable semiconductor device with good electrical characteristics and a display device including the semiconductor device as a switching element. In a transistor including an oxide semiconductor layer, a needle crystal group provided on at least one surface side of the oxide semiconductor layer grows in a c-axis direction perpendicular to the surface and includes an a-b plane parallel to the surface, and a portion except for the needle crystal group is an amorphous region or a region in which amorphousness and microcrystals are mixed. Accordingly, a highly reliable semiconductor device with good electrical characteristics can be formed.

A semiconductor device including a circuit which does not easily deteriorate is provided. The semiconductor device includes a first transistor, a second transistor, a first switch, a second switch, and a third switch. A first terminal of the first transistor is connected to a first wiring. A second terminal of the first transistor is connected to a second wiring. A gate and a first terminal of the second transistor are connected to the first wiring. A second terminal of the second transistor is connected to a gate of the first transistor. The first switch is connected between the second wiring and a third wiring. The second switch is connected between the second wiring and the third wiring. The third switch is connected between the gate of the first transistor and the third wiring.

A low resistivity interface material is provided between a self-aligned vertical heater element and a contact region of a selection device. A phase change chalcogenide material is deposited directly on the vertical heater element. In an embodiment, the vertical heater element in L-shaped, having a curved vertical wall along the wordline direction and a horizontal base. In an embodiment, the low resistivity interface material is deposited into a trench with a negative profile using a PVD technique. An upper surface of the low resistivity interface material may have a tapered bird-beak extension.

An amorphous oxide thin film containing amorphous oxide is exposed to an oxygen plasma generated by exciting an oxygen-containing gas in high frequency. The oxygen plasma is preferably generated under the condition that applied frequency is 1 kHz or more and 300 MHz or less and pressure is 5 Pa or more. The amorphous oxide thin film is preferably exposed by a sputtering method, ion-plating method, vacuum deposition method, sol-gel method or fine particle application method.

An object is to manufacture and provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which a semiconductor layer including a channel formation region serves as an oxide semiconductor film, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed after an oxide insulating film serving as a protective film is formed in contact with an oxide semiconductor layer. Then, the impurities such as moisture, which exist not only in a source electrode layer, in a drain electrode layer, in a gate insulating layer, and in the oxide semiconductor layer but also at interfaces between the oxide semiconductor film and upper and lower films which are in contact with the oxide semiconductor layer, are reduced.

A device for use in a vehicle steering system, said device comprising at least one actuator affixed to a wheel linkage of at least one wheel of said vehicle steering system. The actuator comprises a rotation assembly engagable with a first wheel linkage segment, an electric motor for actuating movement of the rotation assembly via a gear box and one or more sensors integrally contained in the actuator for sensing one or more parameters selected from the group consisting of force, speed, turns and rotation. Rotation of the rotation assembly actuates linear movement of said first wheel linkage segment into and out of said actuator to thereby adjust one or more wheel parameters of said at least one wheel, and wherein said one or more sensors provide real time data to an actuator control unit integral to said actuator to self-adjust rotational parameters of said rotation assembly.

A control arrangement for a hydropneumatic suspension system and a hydropneumatic suspension system are provided. The control arrangement has a pressure supply connection, a return connection, a piston chamber connection adapted to be connected to the piston chamber of a suspension cylinder of the hydropneumatic suspension system, an annular chamber connection adapted to be connected to the annular chamber of the suspension cylinder, and at least one controllable valve arrangement comprising a plurality of switch positions via which the pressure supply connection and the return connection are connectable to the piston chamber connection and the annular chamber connection. The annular chamber connection is in flow connection with the return connection via a pressure-limiting line having a hydraulically controllable pressure-limiting element. The pressure-limiting element has a control input adapted to be acted upon via a control line by a control pressure which is limitable to a predefinable pressure limit.

A ski system includes a ski, a heel binding provided on an upper surface of the ski, a toe binding mount provided on the upper surface of the ski forward of the heel binding, a toe binding releasably mounted to the toe binding mount, and a quick-release locking mechanism for locking the toe binding to the toe binding mount. The quick-release locking mechanism is configured for release by hand.

Interior panels having integrated airbag doors for motor vehicles and methods for making such interior panels are provided herein. In one example, an interior panel comprises a substrate having outer and inner surfaces and an opening extending therethrough. A multi-shot injection molded airbag chute-door assembly is mounted to the substrate and comprises a chute wall that at least partially surrounds an interior space. A door flap portion is pivotally connected to the chute wall and at least partially covers the opening. A perimeter flange extends from the chute wall and has a flange section that overlies the outer surface of the substrate. A molded-in lip feature extends from the flange section and contacts the outer surface to form a seal between the flange section and the substrate. A skin covering extends over the substrate and a foam is disposed between the skin covering and the substrate.

A lightweight folding motorized chair with mechanical traction steering and braking. A folding frame supports the traction wheels and the drive system with hinged frame members configured to mechanically fold the control levers, wheels and periphery components into a substantially flat configuration for easy storage in small spaces. A mix of weight saving choices including: structural materials; mechanical traction control system; lithium ion battery; and overall lightweight design keeps the folding motorized chair at a size and weight that a person can lift into the trunk of a car.

A pre-weakened cover of an airbag module is provided including a layer having an outer show surface and an opposing inner surface. A plurality of first cuts is arranged at a first angle on the inner surface. A plurality of second cuts is arranged at a second angle on the inner surface. Each of the second cuts intersects two adjacent first cuts to form a generally V-shaped pattern.

A pre-weakened cover of an airbag module is provided including a layer having an outer show surface and an opposing inner surface. A plurality of first cuts is arranged at a first angle on the inner surface. A plurality of second cuts is arranged at a second angle on the inner surface. Each of the second cuts intersects two adjacent first cuts to form a generally V-shaped pattern.

A tool comprising a tool body having an opening defined by interior walls extending into the tool body and a casing disposed within the opening. The tool further includes a scintillator material disposed within the casing and a first compressive member disposed within the tool body at a first axial location. The first axial location extends for a fraction of a total axial length of the casing and exerts a first radially compressive force at the first axial location.

A drilling control system monitors and compares drilling and completion operation sensor values and autonomously acts in response to conditions such as a kick or surge. Sensors in various combinations may monitor return fluid flow rate, fluid inflow rate, wellhead bore pressure, temperature of returning fluid, torque, rate of penetration and string weight change. The control system has corresponding control logic to monitor, warn and act based on the sensor inputs. The actions may include the warning of support personnel, closing an annular blowout preventer, shearing drill pipe using a ram shear, pumping heavier fluid down choke and kill lines, disconnecting the riser or various other actions.

A tubular string is advanced with a bottom hole assembly as the hole is drilled and reamed in a desired direction with the aid of directional drilling equipment adjacent the bit. When the advanced tubular forms the desired lap to the existing tubular, the assembly can be configured to cement the tubular and expansion can then be accomplished to fill the annular space and enhance the cement bonding. The expansion equipment can create a bottom bell on the expanded tubular and expand the top end into a bell of the existing tubular so that a monobore is created as the process is repeated with each added string. Numerous variations are contemplated for each single trip including but not limited to the direction of expansion, whether cementing or expansion occurs first, reforming folded tubing in the hole as well as the nature of the expansion tool and pressure control when drilling.

Methods and systems are described for improved drilling operations through the use of real-time drilling data to predict bit wear, lithology, pore pressure, a rotating friction coefficient, permeability, and cost in real-time and to adjust drilling parameters in real-time based on the predictions. The real-time lithology prediction is made by processing the real-time drilling data through a multilayer neural network. The real-time bit wear prediction is made by using the real-time drilling data to predict a bit efficiency factor and to detect changes in the bit efficiency factor over time. These predictions may be used to adjust drilling parameters in the drilling operation in real-time, subject to override by the operator. The methods and systems may also include determining various downhole hydraulics parameters and a rotary friction factor. Historical data may be used in combination with real-time data to provide expert system assistance and to identify safety concerns.

The invention relates to a method and apparatus for opening threaded joints of drilling equipment (6) by striking the drilling equipment (6) with the percussion device of a rock drilling rig (1) and by measuring vibration originating from the drilling equipment (6) during striking. In addition to vibration, measuring means (9) measure a parameter defining at least one additional condition, on the basis of which the decision to stop striking is made.

In one aspect, an apparatus for drilling a wellbore into an earth formation is disclosed, which apparatus, according to one embodiment, may include a drill string configured to be conveyed into a wellbore, wherein an annulus is formed between the drill string and a wellbore wall, a first flow device configured to circulate a first fluid from an annulus to a bore of the drill string, and a second flow device positioned downhole of the first flow device, the second flow device configured to circulate a second fluid from the bore of the drill string to the annulus.