Abstract: A biomimetic tower climbing robot and a tower climbing method thereof are provided. The robot mainly includes a main control body module and clamping and moving mechanism modules; two ends of the main control body module are connected to one clamping and moving mechanism module through an elastic universal joint respectively, two clamping and moving mechanism modules can alternately lock and unlock an anti-fall track of an iron tower, and the main control body module alternately pushes the clamping and moving mechanism module at its upper end upwards and pulls the clamping and moving mechanism module at its lower end upwards to achieve climbing of the robot along the anti-fall track.

Abstract: The present invention relates to all terrain vehicles having at least a pair of laterally spaced apart seating surfaces.

Abstract: Trailering systems are presenting including: a semi-truck trailer; a base positioned along a top surface the semi-truck trailer, where the top surface receives lower cargo, the base including, a pair of forward posts; a forward post mounting rail; a pair of aft posts, a pair of aft posts; an aft post mounting; and an upper deck slidingly engaged with the base, the upper deck including, a pair of forward slides; a pair of aft slides; a pair of side rails; an aft slide mounting rail; a decking; and an airbag system including; a number of forward airbags; a number of aft; and at least one control valve for inflating and deflating the number of forward airbags and the number of aft airbags.

Abstract: The present disclosure provides a self-learning collaborative control method for active steering and yaw moment for a motor vehicle, including a first step of constructing fundamental formulas which are stored in a vehicle ECU, and a second step of calculating an active steering angle ?C and a yaw moment Mc on line by the vehicle ECU according to following sub-steps during a driving process of the motor vehicle, and controlling a driving state of the motor vehicle according to ?C and Mc. The second step includes a first sub-step of collecting raw real-time parameter values, a second sub-step of performing calculation by the identifier and the control target reference model, a third sub-step of calculating ?C and Mc. The present disclosure can realize the self-learning collaborative control of active steering and yaw moment without requiring a system control model and correct a driver's steering operation.

Abstract: A wall suspension rack includes an upper wall seat secured to a wall, a lower wall seat secured to the wall, an upright post mounted between the upper wall seat and the lower wall seat and having an upper block and a lower block, a sliding unit mounted on the upright post and including an upper locking groove and a lower locking groove, a positioning unit mounted on the upright post, an upper protective frame pivotally connected with the sliding unit, and a lower suspension frame pivotally connected with the positioning unit and the upper protective frame. Thus, when the lower suspension frame is moved to the folded position, the upper block is locked in the upper locking groove, and when the lower suspension frame is moved to the expanded position, the lower block is locked in the lower locking groove.

Abstract: The present invention relates to a bicycle parking structure, which includes a base assembly, having a front end portion and a rear end portion; a front frame assembly, pivotally mounted at the front end portion for supporting a front wheel or a rear wheel of a bicycle; a rear frame assembly, disposed at the rear end portion and including a base rod, at least one auxiliary rod and a telescopic rod, wherein the at least one auxiliary rod is detachably mounted at a top end of the base rod, and the telescopic rod is directly assembled to the top end of the base rod or to a top end of the at least one auxiliary rod; and a middle frame assembly, disposed between the front and rear frame assemblies and including two middle connecting plates, two side upright rods, and a bracing member.

Abstract: An apparatus and a method for bicycle anti-theft are provided. When a biometric feature of a user matches a preset biological feature, a brake lever is fixed at a preset position to lock the bicycle.

Abstract: In a saddle riding vehicle (1) including an external device (26) in which an external device (30) is installable, and a connector (27) for connecting the external device, the external device holder is located in front of a rider and above or in front of an instrument section, the connector is provided on one side (24b) in a vehicle body left-right direction, of the instrument section, and a cable supporter (29) that supports a cable (31) connecting to the connector is provided on a same one side (22b) of the instrument section.

Abstract: A retaining system for retaining and releasing an element, in particular an electrical energy store. The retaining system includes a mounting that is configured to accommodate and fix the element, the mounting being configured to removably accommodate the element in the mounting, and an intermediate element that is situated between the element and the mounting and configured to allow a damped motion, in particular for gentle accommodation, of the element in the mounting. The mounting includes a locking bar that is configured to be accommodated in a receptacle in a locking position, or the mounting includes a receptacle that is configured to accommodate a locking bar in a locking position.

Abstract: A handle switch device that prevents a user from being bothered when supplying power, and enables a user to easily check a connection state of a power cord. A handle switch device 10 to be attached to a handlebar 11 of a vehicle 21 is provided with a USB port 18 for supplying power to an external device, and the USB port 18 is directed inwardly with respect to a width direction of a vehicle 21 in a state in which the handle switch device 10 is attached to the handlebar 11.

Abstract: A suspension device includes an outer tube formed of a cylindrical body an inner tube disposed coaxially with the outer tube and provided to be movable relative to the outer tube, a tip end of the inner tube being disposed inside the outer tube, a cable harness extending from an outer side of the outer tube or the inner tube to an inner side and configured to be energized, a stroke sensor configured to detect a movement amount of the inner tube relative to the outer tube, two connection members disposed between the stroke sensor and the cable harness and connecting the stroke sensor and the cable harness, and a correction unit disposed inside the outer tube or the inner tube and configured to correct the movement amount detected by the stroke sensor based on a temperature inside the outer tube or the inner tube.

Abstract: A system for controlling vehicle motion is described. The system includes: a first set of sensors coupled with a vehicle, the first set of sensors configured for sensing the vehicle motion; and a vehicle suspension damper coupled with the first set of sensors, the vehicle suspension damper configured for adjusting a damping force therein, the vehicle suspension damper comprising: a primary valve; a pilot valve assembly coupled with the primary valve, the pilot valve assembly configured for metering a flow of fluid to the primary valve, in response to at least the sensing; and an orifice block coupled with the primary valve and comprising a control orifice there through, the control orifice configured for operating cooperatively with the pilot valve assembly in the metering the flow of fluid to the primary valve.

Abstract: A method for classifying an accident event of a two-wheeled vehicle, in particular a bicycle. The method can be run in the form of an algorithm in a device comprising an analysis unit in order to indicate to the rider or a third party that the two-wheeled vehicle has been involved in a collision or has fallen over using a corresponding generated and/or transmitted item of information. The device can be used in a two-wheeled vehicle, such as a bicycle or in particular in an electric bicycle. However, it can of course also be used in a motorcycle or another single-track vehicle.

Abstract: A handle switch device capable of supplying electric power to an external device without damaging electronic components. A handle switch device 10 comprises a main substrate 20, on which electronic components are disposed, a USB substrate 19, on which a USB port 18 for supplying electric power to an external device is disposed, and a switch housing 12 that houses the main substrate 20 and the USB substrate 19. The main substrate 20 and the USB substrate 19 are disposed so as to be separated from each other.

Abstract: An ergonomic device to provide a removable tray assembly to be attached to a bicycle via one or more means is described, wherein the removable tray assembly may comprise: a tray; an interface element that attaches the tray to a mount via a locking mechanism, such as a quarter turn locking mechanism, wherein the mount comprises a clamping mechanism to attach the mount to the bicycle. According to certain embodiments, the tray may be configured for attachment to a handlebar of a bicycle, such as a stationary bicycle, to provide a platform to hold or place one or more objects.

Abstract: A bearing seat suitable for receiving a bearing includes an annular body, a first outer-radial flange and a second outer-radial flange. The annular body includes a peripheral wall. The peripheral wall has a first end, a second end, an inner matching surface and an outer surface. A thickness difference between the maximum thickness and the minimum thickness of the peripheral wall is within 30%. A portion of the inner matching surface is suitable for contacting and matching with an outer matching surface of the bearing. The first outer-radial flange protrudes from the outer surface adjacent to the first end and extends to the first end. The second outer-radial flange protrudes from the outer surface adjacent to the second end and extends to the second end. The overall structure of the bearing seat is uniform, which can reduce warpage and deformation caused by uneven shrinkage during the injection process.

Abstract: An operating device for a vehicle comprises an outer unit that can be rotated manually, a detection device configured to detect the movement of the outer unit and generate a control signal using a value that characterizes the movement to control a vehicle function, and an actuator unit that contains a magnetorheological medium, which can be or is coupled to the outer unit and is configured to exert a retaining force on the outer unit based on the viscosity of the magnetorheological medium. The operating device also comprises a sensor unit located in the outer unit and configured to generate a hand signal indicating the absence of a user's hand on the outer unit, and a manipulating device for manipulating the control signal on the basis of the hand signal.

Abstract: A lever-operated actuation device for a brake or clutch may have a pump body housing a hydraulic pump provided with a float and a hub rotatably associated with the pump body around a lever pin defining a rotation axis, the hub being associated with a tip operatively connected to the float for its actuation. The pump body may have a pair of fixing ears provided with fixing holes for the lever pin, the lever pin rotatably supporting an associable lever assembly. The lever assembly may have a manual actuation lever and a lever guide suitable to actuate the tip via the hub. The actuation device may have a retention device that keep the hub joined to the pump body, following the removal of the lever pin and the lever assembly for its disassembly/replacement.

Abstract: A hydraulic one-finger two-way acting gear shift operator for a handlebar includes a housing with first and second cylinder chambers, a first and a second piston with first and second piston rods arranged in the first and second cylinder chambers, a first and a second lever arranged to independently push the first and second piston rods and corresponding pistons longitudinally inside the first and second cylinder chambers, wherein the first and second levers are connected to the housing in first and second pivot points, respectively.

Abstract: An anti-rotation bracket configured to engage a horizontal indented vehicle component and fit within an indentation formed within a component attachable to the vehicle is presented. The anti-rotation bracket comprises a flat region having an opening formed therein, the flat region sized to fit within the indentation and an extension integrally formed at a right angle to the flat region, the extension sized to engage the horizontal indented vehicle component such that the extension abuts the horizontal indented vehicle component, thereby inhibiting rotation of the anti-rotation bracket.

Abstract: The insert is metallic and has a first coefficient of thermal expansion (CTE), the insert comprising an outer wall of a first retaining feature; and an undercut shape formed exterior to the outer wall of the first retaining feature such that there is a groove between the outer wall of the first retaining feature and the undercut shape. A composite component having a second CTE different from the first CTE, wherein the insert including the groove is at least partially within the composite component when the composite component is being formed, such that the difference in the first CTE and the second CTE causes the groove between the outer wall of the first retaining feature and the undercut shape of the insert to contract about the composite component to provide a compression to a portion of the composite component within the groove.

Abstract: A motorized self-balancing vehicle is provided. The vehicle may include at least two wheels. The vehicle may include a self-balancing mechanism. The vehicle may include a manual-drive mechanism. The self-balancing mechanism may constantly update the self-balancing vehicle in order to maintain the balance of a rider of the vehicle, while the rider is engaged in human motion on the manual-drive mechanism. The human motion may include pedaling and/or stepping. The vehicle may include an electric motor. The vehicle may include only an electric motor. The vehicle may include only a manual-drive mechanism. The vehicle may include both the manual-drive mechanism and the electric motor. In the embodiment including the manual-drive mechanism and the electric motor, the power generated by the electronic motor may be combined with power generated by the manual-drive mechanism in order to move the vehicle.

Abstract: A cinch direct mount 2× ring system is disclosed. One embodiment discloses a chainring assembly having a drive side crank arm with a chainring assembly interface including a plurality of splines, a circumference, and an axial length. The chainring assembly includes a first chainring having a first outer diameter and a first center assembly shape. The chainring assembly includes a second chainring having a second outer diameter and a second center assembly shape, the second outer diameter being different than the first outer diameter. The chainring assembly also includes a fastener to couple the first chainring and the second chainring with the chainring assembly interface, such that at least one of the first center assembly shape or the second center assembly shape engages with the plurality of splines.

Abstract: A system and method for a bicycle transmission. Specifically, a bicycle transmission having a housing with a first shaft passing therethrough and a set of two cones in opposing parallel alignment disposed within the housing. The first cone engaged about the first shaft, the second cone engaged about a second shaft parallel to the first shaft, the second shaft structured and arranged to have at least a proximal position and a distal position relative to the first shaft. A driver is disposed generally normally about one of the two cones and passing therebetween, the driver structured and arranged to engaging a portion of the first cone with a portion of the second cone when the second cone is in the proximal position. A driver mover structured and arranged to move the driver between the cones when the second cone is in the distal position; and a transfer element joined to an end of the second shaft.

Abstract: A human-powered vehicle control device includes an electronic controller that controls a transmission device to shift a ratio of a rotational speed of a wheel to a rotational speed of a crank axle in stages. The controller controls the transmission device so that the transmission device performs a first shifting action that shifts the ratio by only one stage in a case where a shifting condition is satisfied. The transmission device is controlled by the electronic controller so that the transmission device performs a second shifting action that shifts the ratio by two or more stages in a case where the shifting condition is satisfied and a vehicle state of the human-powered vehicle is a predetermined state. The predetermined state includes a state in which a change amount of a parameter related to the vehicle state is a predetermined amount or greater.

Abstract: The present belongs to offshore wind power engineering field, and particularly relates to a convenient-to-disassemble underwater penetration system for offshore wind power and an operation method thereof. The system includes a penetration device, a suction pump, a sonar ranging module and a control module. The penetration device is configured to be detachably butted with a suction bucket. The suction pump is configured to suck the suction bucket by the penetration device to settle the suction bucket. The sonar ranging module is configured to acquire settlement depth data of the suction bucket. The control module is configured to receive the data and to control the suction pump to work according to it, thereby achieving synchronous settlement of different suction buckets.

Abstract: An intelligent assistance system and a method for berthing and unberthing based on multi-tugboat collaboration are provided.

Abstract: An ammonia bunker delivery system for transferring of ammonia bunker fuel is disclosed. The The ammonia bunker delivery system comprises a primary bunker arm configured to physically support a fluid delivery system across a first distance between a bunker vessel and a receiving vessel. Further, the ammonia bunker delivery system comprises a secondary bunker arm configured to physically support the fluid delivery system to facilitates a second relative motion between the bunker vessel and the receiving vessel. Further, the ammonia bunker delivery system comprises a motion control system configured to coordinate movements of the primary bunker arm and the secondary bunker arm. The fluid control system comprises a connection assembly configured to make a final connection between the ammonia bunker delivery system and the bunker flange of the receiving vessel based on the sensor input.

Abstract: An apparatus for automated rope management on a vessel is described. The apparatus may include a first retraction unit configured to provide rotation about a first rotational axis, a second retraction unit connected to the first retraction unit and configured to provide rotation about a second rotational axis, and a mounting bracket coupled to the first retraction unit and configured for mounting the apparatus to the vessel.

Abstract: Methods for the maintenance of a marine structure having a wind turbine and at least one essentially vertical shaft are described. The methods include the use of an auxiliary floating system having: at least one floating element that remains semisubmerged throughout the process of maintaining the marine structure; at least one coupling structure that connects the system to the floating structure; and contact elements and tightening elements, wherein the contact and tightening elements are secured to the coupling structure and are intended to solidly connect the system to the shaft. Advantageously, this solid connection allows operations for the maintenance of the marine structure to be carried out in a manner that is efficient and safe for maintenance workers and for the systems involved in the operations.

Abstract: A system, adapted to determine that automatic docking of a boat is completed. The system including a control unit including a processor configured to switch a control mode of the control unit to an automatic docking mode; output a control signal for controlling an automatic steering of the boat when the control mode is switched to the automatic docking mode; obtain a vibration that is exerted on the boat, wherein, when the control unit is in the automatic docking mode, the control unit is configured to end the automatic docking mode when the control unit detects the vibration.

Abstract: A paddlecraft with a recess in its deck for a hookah diving compressor is disclosed where a user can paddle to a dive site and dive there without removing the compressor from the recess. An interchangeable insert for the recess supports different shapes and sizes of compressors. For a water-cooled compressor, the recess admits water from beneath the paddlecraft, or part of the compressor protrudes through the recess into the water beneath. A lid for the recess with an attachable tube feeds air to the compressor. An airline connection point is integrated into the paddlecraft, readily allowing connection and removal of an airline, or two or more airlines via an adaptor. The paddlecraft can also house an air reserve tank, allowing the user to dive without removing it. If the paddlecraft is an SUP, part of the SUP deck preferably functions as an air reserve tank.

Abstract: An individual self-contained breathing apparatuses of closed cycle is proposed, including an air system, including a compensatory cylinder with compressed gas, a reducer and a manometer; a gas analyzing system; a regenerative device including reactors with cartridges with oxygen regenerating agent; a breathing circuit including a face mask, a space under the face mask, a breathing bag, a valve for releasing pressure in the breathing circuit; connecting air ducts for connecting the breathing circuit to the regenerative system and the air system, whereas all components are positioned in monoblock housing. The apparatus includes no supply of the breathing mixture. The apparatus can be used for recreational diving, technical diving, professional diving or rescue purposes.

Abstract: The system and method of retractable solar arrays for underwater vehicles. In some cases, the retractable solar arrays for underwater vehicles contain anti-biofouling mechanisms. The retractable solar arrays may extend in a linear or a fan-like manner. In some cases, the solar array may be wrapped around the outside of the underwater vehicle or within a cylindrical housing. In some cases the solar array is a single flexible member with a series of connected panels.

Abstract: An exhaust pipe has an upstream-side exhaust pipe extending downward from an engine to house a catalyst for exhaust gas purification, and a downstream-side exhaust pipe located downstream of the upstream-side exhaust pipe, and extending upward from the catalyst and then bending downward. Under a configuration in which an exhaust pipe is disposed below an engine, with a simple configuration, a catalyst is hardly exposed to water.

Abstract: An outboard motor includes an outboard motor body including a propulsion generator and an engine to drive the propulsion generator, a pair of clamp brackets, a swivel bracket provided between the pair of clamp brackets and rotatable in an upward-downward direction with respect to the pair of clamp brackets while supporting the outboard motor body, and an electrical wiring extending from a position between the pair of clamp brackets upward to the outboard motor body through the swivel bracket and connected to the outboard motor body.

Abstract: A ship hydrogen hybrid power propulsion system and a method thereof are provided. The ship hydrogen hybrid power propulsion system includes a motor, a propeller, a power battery, an external motor controller, an internal motor controller, a hydrogen fuel cell, a hydrogen internal combustion engine, and a hydrogen storage tank. It combine the hydrogen fuel cell with the hydrogen internal combustion engine, and the hydrogen fuel cell is combined with the power battery and dynamically coupled with the internal motor and the external motor. Only a single hydrogen energy is needed, which is conducive to the layout and integration of the power system and achieves zero carbon emissions. Compared to the current dual motor power system, it has high integration, simpler power coupling, and a wider range of power output, making it particularly suitable for the high load and high-power output requirements of heavy-duty ships.

Abstract: In a system for controlling a watercraft, when a first mode is selected, a controller determines a route on which a single or a plurality of specified spots including a destination are located, and controls a marine propulsion device such that the watercraft moves along the route with a bow thereof being kept oriented in a predetermined cardinal direction. When a second mode is selected, the controller controls the marine propulsion device such that the bow of the watercraft is kept oriented in the predetermined cardinal direction without determining the route. The controller obtains a position of the watercraft. In the first mode, the controller determines whether or not the watercraft has passed through the destination. When the watercraft has passed through the destination in the first mode, the controller performs a mode switching from the first mode to the second mode and controls the marine propulsion device in the second mode.

Abstract: The present specification relates generally to unmanned aerial vehicles, and specifically to a vertical take-off and lift unmanned aerial vehicle configured for high speed, long-distance flight, and vertical take-off and lift, while carrying a significant payload. The aerial vehicle includes a first propeller and a second propeller, each comprising at least two blades and each disposed on opposite lateral edges of the aerial vehicle; a tail segment forming a trailing edge of the aerial vehicle, wherein the tail segment comprises: an elevator; and a first wing and a second wing, each comprising an aileron. The aerial vehicle further includes four fins, wherein the four fins are affixed to lateral edges behind the first propeller or the second propeller and configured as endplates; a motor; and a power supply.

Abstract: A low-density structured material with good mechanical stability that can be used for three-dimensional structures, and methods to make and use same. In embodiments, the low-density structured material includes a first surface of interconnected polyhedrons, a plurality of tetrahedral arrangements whose base is the polyhedrons of the first surface, a second surface that is a web attached to the tetrahedral vertices of the tetrahedral arrangements, and panel materials overlying the web. The low-density structured material can be utilized in a variety of different structures.

Abstract: An aircraft door including a retaining device for a deployable evacuation device, the retaining device having at least: a beam; a first retention member fixed on a second end of the beam by a detachable clip, the first retention member being connected to the deployable evacuation device; a second retention member, which can be coupled to the first retention member, mounted on the door frame; retraction devices that moves between: an activated position, in which the second retention member is on the trajectory of the first retention member, and a deactivated position, in which the second retention member is outside the trajectory of the first retention member.

Abstract: Aircraft door seals, especially door seals for aircraft cargo doors, include individual door seal sections joined together by a lap joint assembly. The door seal sections may have abutted ends establishing a seal junction, and a lap joint junction seal assembly to sealingly join the abutted ends of the door seal sections, wherein the lap joint junction seal assembly includes (i) a lap joint member having a lap joint base and a lap joint shelf extending from the lap joint base and sealingly engaged with a lower surface of the door seal sections over the seal junction, and (ii) an interior support spigot inserted within the interior space of each of the door seal sections at the abutted ends thereof. Each of the door seal sections may be a hollow profiled door seal defining the interior space and formed of an elastomeric sealing material.

Abstract: A window installation includes a phase-change filler material sealing an outer edge of the window, and coupling the window to a frame around the window. The filler material in a solid state rigidly holds the window in place. When the filler material is in a liquid state it allows the window to float in its coupling to the frame. There may be supports within the rigid material that contact the window, but allow the window to expand or contract by sliding along the supports. The installation may be useful in situations where the window is subjected to thermal shocks, or other sorts of heating. The installation may be used for a sensor window, and may be part of a hypersonic vehicle.

Abstract: A pin joint assembly is disclosed having a first lug and a second lug, a pin extending through the first and second lugs, a U-shaped bushing between the first lug and the pin, wherein the U-shaped bushing includes a first end flange and a second end flange that extend radially outwards and retain the U-shaped bushing to the first lug, and wherein the U-shaped bushing includes a bearing surface between the first and second end flanges on which the first lug is slidable.

Abstract: An aircraft has a fuselage, a wing assembly, and a pair of struts. The wing assembly has a center wing structure and a pair of outer wing structures. The center wing structure is coupled to the fuselage at a wing-fuselage joint, and has a pair of engine mounting locations respectively on opposite sides of a wing centerline. Each of the struts is coupled to the fuselage at a strut-fuselage joint, and to one of the outer wing structures at a strut-wing joint. Each strut-fuselage joint is located below and aft of the wing-fuselage joint. Each outer wing structure is coupled to the center wing structure at a mid-wing joint located no further inboard than the engine mounting location, and no further outboard than the strut-wing joint.

Abstract: An unducted fan having variable pitch blades for an aircraft or wind propulsion system is described. The fan includes a hub provided with housings pivotally receiving vanes about radial axes, and an outer casing of the hub into which circular openings of the housings open. Each vane includes a root which is rotatably mounted in the associated housing, a radially oriented blade and a disc-shaped platform extending from the blade to an edge of the circular opening. The blade includes at least one skin which includes a free lower edge facing the side of the root, wherein the platform is attached to the free lower edge of the skin.

Abstract: A propeller assembly for an aircraft includes a main shaft rotatable about a propeller axis, a rotor hub mounted to the main shaft, and a plurality of blades coupled to the rotor hub. Each blade is rotatably coupled to the rotor hub for rotation about a blade rotation axis. A control system rotates each blade about the corresponding blade rotation axis and includes a ball screw coupled to the main shaft for rotation about the propeller axis and configured to translate along the propeller axis, an actuator beam mounted on the ball screw, and a ball nut coupled to the ball screw. When the ball nut rotates relative to the ball screw, the ball screw translates relative to the main shaft along the propeller axis. A differential transmission is configured to rotate the ball nut relative to the ball screw such that the ball screw is translated.

Abstract: Provided is an airflow control system for controlling airflow flowing over an upper surface of an aircraft. The airflow control system includes: a blowout port that is provided on a forward side of the upper surface of the aircraft to blow out the airflow; a suction port that is provided closer to the forward side than the blowout port to suck outside air; a fan that is provided on a rearward side of the blowout port to suck air flowing from a forward side and to discharge the air to a rearward side; and a compressor that is provided in a channel extending from the suction port to the blowout port to increase pressure of the outside air sucked from the suction port and to pressure-feed the resulting outside air to the blowout port.

Abstract: Flow control ducted fans are disclosed. A disclosed example flow control apparatus for use with an aircraft includes a duct defining an inner cavity with a primary flow path, a fan disposed in the inner cavity, an aperture on an exterior surface of the duct and upstream from the fan, the aperture fluidly coupled to the inner cavity to define a secondary flow path, and a door to control a degree to which the aperture is opened.

Abstract: Active surface structures comprise an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators, and a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a first state, and a second state that is less textured than the first state. Active surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active surface structure is actively controlled.