Abstract:
An air jet game comprising an air jet conduiting member having a plurality of air jet outlets and a controller adapted to selectively control at least partially, the flow of air out of the air jet outlets in order to move an object located in an air flow path of the outlet in a desired direction.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to airjet object movement systems, and more particularly, to an airjet board game. 
     2. Prior Art 
     Systems for supporting objects with a controlled fluid flow are known. For example, U.S. Pat. No. 6,004,395, which is commonly owned by Applicants&#39;assignee and the disclosure of which is incorporated herein by reference, discloses a valve array for supporting objects, such as paper, with controlled fluid flow. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to, in a first aspect, an air jet game. In one embodiment, the air jet game comprises an air jet conduiting member having a plurality of air jet outlets and a controller adapted to selectively control at least partially, the flow of air out of the air jet outlets in order to move at least one object located in an air flow path of the outlet in a desired direction. 
     In another aspect, the present invention is directed to a method of controlling the movement of an object in an air jet board game. In one embodiment, the method comprises detecting a position of the object, and moving the object in a desired direction by one or more air jets in the board. The step of moving comprises each air jet being selectively energized based upon the detected position of the object and a respective control input corresponding to the desired direction and desired velocity of the object. Points are scored in the game by moving the object past a goal area on the board. 
     In a further aspect, the present invention is directed to an air jet object mover game. In one embodiment, the air jet object mover comprises an array of air jets, an array of object sensors, and a first controller and a second coupled to the array of air jets and the array of object sensors. Each controller is adapted to selectively control the movement of the object over the array of air jets by selectively activating one or more of the air jets based upon on a detected position of the object by the object sensors and a desired direction of movement of the object. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects and other features of the present invention are explained in the following description, taken in connection with the accompanying drawings, wherein: 
     FIG. 1 is a block diagram of one embodiment of an airjet board game incorporating features of the present invention. 
     FIG. 2 is a block diagram of one embodiment of an airjet system incorporating features of the present invention. 
     FIG. 3 is a cross-sectional view of a pair of airjets levitating and accelerating an object in one embodiment of a system incorporating features of the present invention. 
     FIG. 4 is a graphical representation of the measured lateral force per jet versus pressure drop across a jet and plenum pressure for one embodiment of a system incorporating features of the present invention. 
     FIG. 5 is a cross-sectional view of one embodiment of an electrostatic flap valve incorporating features of the present invention. 
     FIG. 6 is a pictorial representation of one embodiment of a flap valve configuration incorporating features of the present invention stroboscopically observed from above and from the side. 
     FIG. 7 is a graphical representation of valve conductance versus valve voltage for one embodiment of a flap valve configuration incorporating features of the present invention. 
     FIG. 8 is a side elevational view of a section of one embodiment of single side air table incorporating features of the present invention. 
     FIG. 9 is a side elevational view of a section of one embodiment of a two-side air channel incorporating features of the present invention. 
     FIG. 10 is an elevational view of one embodiment of an airjet module incorporating features of the present invention. 
     FIG. 11 is a flowchart of a control architecture for one embodiment of a system incorporating features of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a block diagram of a game  10  incorporating features of the present invention is shown. Although the present invention will be described with reference to the embodiments shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used. 
     Generally, the system or game  10  comprises an air jet conduiting member  12 , also referred to as an airjet board, and a movable object  44 . The game may also include a controller  14  that is adapted to allow a user to control the position and movement of the object  44  on the board. The game  10  may also include one or more positioning control devices  20 . In one embodiment, the positioning control device  20  can comprise a joystick. A user can use the joystick  20  to control the position and movement of a movable object  44  on the board  12 . It is a feature of the present invention to allow one or more users to control the movement of one or more objects  44  over the board  12  in a game. A game can involve controlling the flow of air along a surface of the board  12  in order to move the object over the board  12 . In one embodiment, the object  44  could be levitated over the board  12 . For example, a game may comprise a user playing against another user or a computer as an opponent, and attempting to control the movement of one or more objects  44  on the board  12 . 
     In one embodiment, the airjet board  12  comprises a plurality of airjets  42  and sensors  38 . The member  12  may also include one or more connectors  82  for coupling the member  12  to the controller  14 , coupling the member  12  to another member  12 , or for coupling the member  12  to other suitable devices. In one embodiment, the game  10  also includes the positioning control device  20  that is adapted to control the movement of the object  44  along or over the board  12 . The positioning control device  20  may be coupled to the controller  14  and can be adapted to provide positioning commands to the controller  14 . In one embodiment, the positioning device  20  can be an integral part of the controller  14 . In an alternate embodiment, the game  10  can include such other suitable components for controlling the position of an object with an airjet. 
     As shown in FIG. 2, in one embodiment, the air jet conduiting member  12  can comprise a valve board  40  and a sensor board  36 . Generally, the valve board  40  comprises an array of airjets  42  and may include a plurality of openings  37  for sensors  38 . The sensor board  36  comprises an array of sensors  38 . Generally, the airjets  42  can be used to move an object on the board, for example by rolling, and/or levitate the object  44  above the board  12 . The sensors  38  detect the position of the object  44  on or over the board  12 . In an alternate embodiment, the game  10  may include such other suitable components for moving an object  44  with an air jet system. It is a feature of the present invention to provide a system for moving an object  44  in three degrees of freedom without making physical contact with the object  44 . Generally, the object  44  comprises a lightweight flexible medium, such as for example, a sheet of paper or a disk like object that can be levitated over the board  12 . The disk can comprise any suitable material, such as for example, plastic. In an alternate embodiment, the object  44  can make contact with the board  12  at a point and be moved along the board  12  by the airjet  42  in a rolling or sliding fashion. For example, the object can comprise a hollow or semi-hollow sphere or disk which rolls on the board and can comprise any suitable material such as for example, plastic. 
     FIG. 3 is a cross-section of an object  44  being levitated and accelerated by a pair of airjets  42  in an air channel  46 , in an exemplary 2-sided embodiment of the present invention. Arrays of simple cylindrical orifices pass through the plates oriented, in one embodiment, at approximately 45 degrees with respect to the plate normal. A small pressure gradient along an orifice passage  42  creates a jet of air as shown in FIG.  3 . In an alternate embodiment, any suitable number of airjets in any suitable orientation can be used to move the object  44 . It is a feature of the present invention to levitate and move an object  44  at high accelerations and peak velocities. As shown in FIG. 3, three dimensionally confined airjets  42  impinge on the sheet  44  and apply localized shear stress on the sheet  44 . Fluid jets directed with a velocity component normal to the surface of the object  44  must have their flow redirected. Conservation of total momentum implies some direct momentum transfer to the object  44  along the channel  46 . Another force acting on the object  44  exerts a shear force on the surface of the object  44  due to the viscous momentum exchange in a velocity gradient. The viscous drag slows the fluid, or air, and accelerates the object  44 . The boundary layer is the fluid or air region adjacent to the surface of the object in which the velocity transitions from the velocity of the solid bounding surface to nearly the fluid velocity far from the surface. In one embodiment, the boundary layer thickness, approximately 1 mm, is considerably greater than the root mean square height variations characterizing the texture of most paper stocks. Thus, the shear force exerted is approximately independent of the surface texture of the object  44 . 
     The downstream air spreads out laterally and vertically, and produces far less lateral force on the sheet  44 . Forces are dominated by those created in the jet impingement zones. Generally, air spreading out in the channel  46  downstream slows and disperses. At the low Reynolds numbers encountered here (Re&lt;1000), flows are laminar. The lateral forces on the sheet  44  are given by the Newtonian law of friction, F=μdv x /dy, where μ is the dynamic viscosity, V x  is the velocity along the channel  46 , y is the dimension perpendicular to the channel  46 . The shear velocity gradient, dV x /dy, is far greater in the impingement zone than downstream. 
     The shear force on the sheet  44  depends weakly on the incident angle and distance of paper from jet plate  48 , and is approximately proportional to the pressure drop across the airjet  42 , as is represented in the graph of FIG.  4 . Plenum pressure, as will be described below, is generally higher than the pressure across the jet  42  for the valve embodiment described. In an alternate embodiment, the plenum pressure can be of any suitable magnitude relative to the pressure across the jet  42 . In one embodiment, the magnitude of the lateral force is typically 0.1 mN per jet. 
     The flow of air through an airjet  42  can generally be modulated by a valve mechanism  70  as shown in FIG.  5 . In one embodiment, the valve mechanism  70  can comprise a plenum  52 , an electrostatic flap valve  50 , and an airjet  42 . In an alternate embodiment, the valve mechanism  70  can include any suitable valve mechanism and structure adapted to control the flow of air to the jet  42 . Although the embodiments of the present invention described herein are discussed in terms of “air”, “airjets” and “air flow”, any suitable fluid can be used other than including “air”. 
     The electrostatic flap valve  50  is generally capable of switching on and off jet flows that can provide several tenths of a milli-newton of shear force. The flap valve  50  generally includes an upper electrode  64  and a lower electrode  62 , across which an electric potential can be applied. The flap valve  50  can comprise any suitable material such as for example, polyester. The electrode material  64  can comprise an electrically conducting material, such as for example, aluminum or copper. In one embodiment, the lower electrode  62  and upper electrode  64  are electrically connected to a common potential, such as for example, a ground potential. As shown in FIG. 5, in that embodiment, pressurized air in the plenum  52  blows through a valve orifice or via  60  and out of the airjet  42  if there is no voltage drop across the flap valve  50 . When a voltage is applied between electrodes  62  and  64 , the upper electrode  64  is. attracted to the lower electrode  62 . The flap valve  50  closes and seals the valve orifice  60 . 
     The fabrication of flap valve mechanism  70  can generally comprise fabricating a 2-sided or multilayer printed circuit board  58  (“PCB”) by standard means with an array of 1.5 mm diameter holes. The holes act as vias both for connecting the lower and upper copper traces on the PCB  58  as well as for providing air to the valve  50  from the plenum  52  below the PCB  58 . In one embodiment, a gasket plate  56  can be laminated to both sides of the PCB  58 . The gasket plate  56  can comprise an acrylic plate 2 mm in thickness, with thin film adhesive layers. In alternate embodiments, the gasket plate  56  can comprise any suitable material, such as for example, FR 4 , ceramic or flex. The gasket plate  56  can be laser cut to pattern the gasket around the valve orifice  60 . In one embodiment, a supporting layer  54  can be used to facilitate handling and dimensional stability of the thin film. The supporting layer  54  can comprise an aluminized, 6-micron thick polyester sheet laminated onto a 250 microns thick polyester layer, although other suitable supporting materials may be used. After laser cutting, the thin film is aligned and bonded to the bottom of the gasket plate  56 . A jet plate  48  including the airjets  42 , can be aligned and laminated to the gasket plate  56 . In one embodiment, the jet plate  48  can be laser cut to form 1 mm diameter holes tilted at 45° and oriented in the four cardinal directions to form the airjets  42 . In an alternate embodiment, the jet plate  48  can comprise a multiple layer structure with holes spatially shifted by a fraction of a hole diameter in each layer which are aligned and stacked to provide the tilted air jets  42 . Each layer in the multilayer structure can be formed by drilling, die cutting or photolithography, for example. The upper valve assembly  68 , including the gasket plate  56  and the jet plate  48 , can be affixed to the PCB  58 . In one embodiment where a polyester sheet is used as the supporting layer  54 , the polyester sheet is removed from the polyester flap valve array and the upper valve assembly  68  is laminated to the PCB  58 . In one embodiment, a 50 micron thick adhesive can be used that compresses against the flap valve  50  material and bridges to the PCB  58 . 
     In order to manipulate a flap valve  50  in an array of valves on the board  40 , a common voltage is applied to the top electrode  64  of all flap valves  50  and the bottom electrodes  62  of each flap valve  50  are addressed individually. The electrostatic forces must be satisfactory to overcome the aerodynamic forces associated with flows necessary to adequately accelerate the object  44 . 
     FIG. 6 shows a flap valve  50  being optically strobed at variable delays after the valve voltage is raised or lowered. The images obtained on video camera through a microscope show the stages of valve opening and closing seen from above (upper frames) and from a side (lower frames). The figures in the upper row A show selected frames for a flap valve  50  opening and lower row B shows a sequence while the flap valve  50  is closing. The plenum pressure in the valve mechanism  70  for the embodiment shown was 0.5 kPa (1/200 of an atmosphere) above atmosphere, the closing voltage was 300 V, and the opening voltage was 0 V. The flow through the opening valve under these conditions was 0.02 L/s.1. In the closing sequence the flap valve  50  first zips rapidly up to the orifice  60  then slows where the curvature increases as the flap valve  50  starts to close off the flow through the orifice  60 . As the flap valve  50  approaches closure a “tunnel” is formed in the last one or more milliseconds before complete sealing. The closing time is taken to be the time when complete sealing occurred. On opening, the center of the flap valve  50  balloons up and the effective area of the aperture increases until the declining electrostatic force of the remaining flap can no longer withstand the increasing pneumatic force. After release, the flap valve  50  quickly rises to about half height then drifts more slowly to a larger height. The higher the pressure the faster the flap valve  50  is blown open. Similarly for high pressures and flows, the flap curvature is increased, the electrostatic forces are decreased, and the flap valve  50  takes longer to zip shut. Beyond about 1 kPa, under the conditions used here the flap valve  50  no longer can close. By changing gasket shape, valve orifice diameter, etc., closing pressure drops can be increased to several kPa. 
     Generally, the pressure is dropped across the flap valve  50  and airjet  42  in series. The impedance of a 4 mm long, 1 mm diameter jet  42  is very nearly equal to that of a 1 mm diameter aperture. The flow through an aperture at these small pressure drops is proportional to the square root of the pressure drop. The impedance, ΔP/F, where F is the mass flow under the pressure gradient ΔP, is thus not a constant. Series impedances add in quadrature. For an inlet aperture with area A i  and outlet aperture with area A o , in series, the pressure at the midpoint, i.e. in the gasket volume, rapidly equilibrates to P=P o +ΔP i /(r 2 +1), where r is the ratio A o ,/A i  and ΔP i −P o  is the pressure drop from plenum  52  to jet exhaust. This is useful in determining the behavior of a flap valve  50  in conjunction with a particular diameter jet  42 . 
     FIG. 7 is a schematic drawing of the hysteretic behavior of one embodiment of the present invention showing the steady state valve conductance as a function of valve voltage for a plenum pressure of 0.5 kPa. At zero volts the compliant flap valve  50  is blown open into a stable, inflected curve. For applied voltages less than 220 V the flap valve  50  zips up to the orifice  60  and stops. For voltages higher than 220 V the flap valve  50  zips to closure with the total elapsed time to completion decreasing with increasing voltage. Similarly, dropping the voltage to greater than 120 V does not allow the flap valve  50  to open because the electrostatic force is much greater when the flap valve  50  is shut than when it is open because of the finite curvature in the latter case. Thus, the voltage must be increased for an open flap valve  50  to overcome this barrier resulting in a hysteretic behavior. 
     Below 120 V the flap valve  50  is opened by the held-off pressure with times as shown in FIG.  7 . Thus, the flexible electrostatic valves described here can be seen to have large stroke but have a region of sufficiently low curvature so that the gap between electrodes is small enough to provide electric fields strong enough to zip the membrane along. FIG. 7 also plots the opening times at low voltages and the closing times at high voltages. As shown, the higher the voltage the faster the flap valve  50  snaps shut, and the lower the voltage the faster the flap valve  50  pops open. 
     Another method used to characterize valve response, a method that is more functionally relevant, utilizes a silicon membrane pressure sensor, stripped of its packaging. The sensor is positioned at the impingement zone of a jet  42 . The time dependence of the stagnation pressure of the jet, and therefore the time dependence of the flow in the channel, is determined from the response of the sensor. The measured flow generally follows the driving pulse except that both turn-on and turn-off have approximately a 1 ms delay and have &lt;1 ms rise and fall time. There is a seeming discrepancy between the flow response times and the stroboscopic measurements of flap transition times, for both closing and opening the flow transitions occur more quickly. The difference arises predominantly from the variation in flow impedance of the valve when the flap valve  50  is near closure. The impedance of the flap valve  50  when the flap is near the lower electrode  62  increases strongly as the gap decreases. The impedance of the “tunnel” feature is much higher than that of the open valve. Therefore, the time to full visual closure overestimates the time of significant flow. Similarly, the impedance of the valve is limited by the impedance of the jet  42  when the flap valve  50  is well above the electrode  62 . Therefore, when the flap valve  50  rises beyond a height of about d/4, where d is the diameter of the valve orifice  60 , the flow is saturated. So again the stroboscopic estimate exceeds the flow response time. Another characteristic feature of the flow response is the approximately 1 millisecond delay between voltage drive and flow response. This is a convolution of the flap response time and the time constant for pressurizing and de-pressurizing the gasket volume, estimated to be 1-2 millisecond. Lifetime tests were run on an array of 120 valves by driving the valves in parallel with a 10 millisecond repetition time. Driving was terminated after 400 million repetitions with no valve failures and negligible charge injection-induced voltage shifts. The flap valves  50  are thus shown to be very reliable, most likely because the small curvatures of the flaps lead to negligible plastic deformation of the polyester or aluminum. Furthermore, having the aluminum above the plastic minimizes abrasion of both the aluminum and copper. 
     To enable controlled manipulation of the object  44 , the position of the object  44  must be sensed. As shown in FIG. 2, the air jet member assembly  12  may also include a sensor board  36 . Generally, the sensor board  36  comprises an array of sensors  38  that are adapted to detect the position of the object  44  in two or more dimensions. In one embodiment, the sensor board  36  can comprise an array of linear CMOS sensor bars  38 , having for example, an internal pixel pitch of 64 microns, to detect edge positions of the object  44  in two dimensions. In an alternate embodiment, any suitable means to detect a position of the object may be used, such as for example, a distributed optical sensor on the same PCB containing the actuators and computational electronics or an amorphous silicon or organic sensor array. In one embodiment, the levitated object is illuminated, either in transmission or reflection, and the contrast between the light levels with the object  44  absent and present are detected optically as edge transitions. For example, as shown in FIG. 9, Lambertian illumination from above casts a shadow of the object  44  which is imaged by a SelFoc™ array  76  onto the CMOS sensor  38 . In one embodiment, a collimator  74  may overlay the sensor array  36  as shown in FIG.  8 . All 1280 gray level pixels of all sensors are latched simultaneously and then clocked out every millisecond and binarized using a processor-set threshold. As shown in FIG. 2, a field programmable gate array (FPGA)  26  can be used to filter the outputs into acceptable edge transitions. The transitions can be passed to a digital signal processor (DSP)  18  to infer the position and rotation state of the object  44 . In one embodiment, the desired position and orientation for the object  44  can be entered into the DSP  18  from a canned trajectory or from a three degree of freedom joystick  20  as shown in FIG.  2 . Alternately, any suitable positioning device can be used to enter a desired position and trajectory of the object  42 . The DSP  18  compares the sensed state of the object as determined by the sensor array  36  with the desired state as determined by the joystick  20 , and generates the forces and torques required to null the differences. The DSP  18  is generally adapted to convert the transitions into a spatial map of edge crossings, and can generate a rectangle, a shape or multiple shapes which best fit through those transitions. A force allocation algorithm can then be used to determine which valves  50  should be opened and closed to best approximate the desired forces and torques. The commands can then be sent to another FPGA  26  which is adapted to drive the high voltage arrays  30  to enable the valve  50  transitions. In one embodiment, the control loop is pipelined with the sensing so that the entire feedback looping occurs within approximately one millisecond. 
     In the embodiment shown, control in the system  10  is centralized. Alternate embodiments may utilize distributed computation and control. The algorithm, operating with an approximately 25 Hz closed loop bandwidth, is a simple first order lead controller which can use history to disambiguate nearly equivalent fits of rectangles to the set of edge locations. Position is generally held to approximately 25 microns for statically positioned levitated objects, and tracking accuracy is approximately 75 microns for rapidly moving trajectories (such as circles and steps). Although the present invention is described in terms of moving an object, it should be understood that the controller can also be used to hold a relatively stationary position of the object  44 . Generally, the joystick  20  is used to input a command signal to the controller corresponding to a desired direction of movement of the object  44 . The joystick  20  may also be adapted to input a desired velocity for the object  44 . In alternate embodiments, the joystick  20  can provide any suitable commands to the system  10 . In one embodiment, the command signal may include a command to hold a position of the object  44 , in which case the object  44  can be levitated in a relatively stationary position. 
     A control architecture flowchart for one embodiment of the present invention is shown in FIG.  10 . Force and torque commands (Fx, Fy, and Tz are fed through the controller  14  in order to allocate the valve  50  actuators as indicated in blocks  102  and  104 . The actuator allocation generally includes control commands for each of the 576 valves in a single sided embodiment of the air table described above. In an alternate embodiment, an air table could include any suitable number of valves. Generally, the force and torque commands depend from a position command(s) (x,y,θ) from the position control device  20  or devices, and the detected position(s) (x,y,q) of the object or objects. The actuator commands are processed through the paper and actuator dynamics as indicated in block  106 . The detection of the object  44  can be processed through sensor-edge processing as indicated in block  108 , which can then be used to determine the position in terms of coordinates (x,y,q) of the object as indicated in block  110 . The control loop depicted in FIG. 11 allows for accurate control and movement of an object  44  over a board  12 . 
     The system  10  can generally be operated either as a single sided air table  80  as shown in FIG. 8 or as a 2-sided air channel  90  as shown in FIG.  9 . In an alternate embodiment, the system  10  may be operated with any suitable number of sides, such as for example, a tunnel. As shown in FIGS. 8 &amp; 9, the system  10  can include a blower  72  to supply air to the plenum  52 . The system  10  can include any suitable number of plenums  52  and blowers  72 . The system  10  can also include high voltage drivers  74 . Generally, the 2-sided system  90  has better performance characteristics due to the increased actuation authority and the stablilization from a double sided air bearing created by the air flow from two jets  42  impinging on the object  44 . The 2-sided air bearing effectively stiffens the object and maintains the sheet at a fixed height (approximately 2 mm above the jet plate  48 ) independent of plenum pressure as long as both top and bottom plena  52  are at the same pressures. 
     FIG. 10 shows one embodiment of a 12 inch×12 inch 30.48 cm × 30.48 cm airjet object mover module  12  or board game. Although this embodiment comprises arrays of square modules, and suitable size or shape of array can be used, such as for example circular arrays as shown in FIG.  12 . In the example shown in FIG. 10, each actuation PCB  58  consists of 576 valves  50  and jets  42 ; 144 (or one per square inch) point in each of the four cardinal directions. The jets  42  are interleaved with the sensor bars  38 . Sixteen element arrays  78  comprise flap valves  50  and associated jets  42 . The black bars are SelFoc™ arrays  76 . By invoking an image of valve openings arbitrary force fields can be applied to the levitated objects  44 . Object motions with three degrees of freedom (x, y, θ) can be controlled, and gray levels of force can be asserted by changing the number of jets  42  or the time of actuation of jets  42 . 
     Connectors  82  are provided for coupling to the controller  12  and other related components or devices. In one embodiment, an airjet module  12  is adapted to be connected to one or more other airjet modules  12 . In this manner, a series of airjet modules  12  can be connected in order to provide a larger platform or a pathway along which an object  44  can be moved. 
     One feature of the system  10  is that due to the individual airjet  42  control, pieces of paper or other objects  44  can be moved arbitrarily in a two-dimensional plane. Although the object  44  is described herein as being flat, any object  44  that can be moved, roller or levitated by an airjet  42  or series of airjets, can be used. In one embodiment, a board game application of the system  10  can have one or more players competing to move/block playing pieces  44  using one or more position control devices  20 , such as one or more joysticks. For example, an airjet board game incorporating features of the present invention could include two 3-degree of freedom joysticks  20  to allow two or more users to move one or more objects  44  past each other toward some goals. In another embodiment, the airjet board game could include an individual user playing against a computer. 
     The system  10  allows for maneuverability of the playing pieces as well as programmability of the field of play. Games may include for example, soccer, hockey, and obstacle races. Programmable fields of play could include for example, hills and tunnels, where the physical “terrain” of the playing field or board  12  could be modified by the computer. 
     In another embodiment, the system  10  could be adapted to move sheets of paper along a path or sort tiles into desired patterns. 
     The architecture described above provides for the control of thousands of actuators and sensors. The system described above has a largely centralized control architecture. The scalability of control electronics and algorithms for assemblies of numerous independent agents, particularly for human-scaled systems demands distributed computation and control. Systems tightly integrating many actuators, sensors, computational nodes and communication, can be called “smart matter”. 
     In designing smart matter systems the boundaries between the digital and analog worlds are blurred. An example of a smart matter approach to achieve a scalable control design is an analog “market wire” developed to perform the force allocation tasks. In one embodiment of the airjet module  12 , each set of four actuators, pointing in four different directions, is a force agent. One or more sensors  38  can be associated with each force agent. An analog circuit and/or micro-controller can be associated with each agent. Agents can thus sense and act locally, but coherent, larger scale actions are required. PCBs can have many layers of metal for little extra expense. An agent, such as a controller  14 , can request more of a commodity, say force in the x direction, by sourcing current onto such a plane, a market wire, basically a capacitor. The voltage (the “price” of the x-force) rises. Each agent has vias connecting to the market wire(s). Producer agents, the airjet foursomes, consider supplying the x-force. First the local sensor  38  looks up at the object  44 . If it is there it makes sense to participate. Should it turn on? Locally it has a “marginal utility function” which says, in effect, if the voltage is above a certain threshold, turn the x-valve on. Then sink current from the x-force market wire, dropping the “price”. Another agent, perhaps far away, but also under the sheet, asynchronously decides that the price has now dropped below its threshold and decides not to turn on. The desired force is thus provided almost instantaneously. The mechanism is easily scalable. It is essentially independent of the number of agents on a board. If another board is added to the system, the market wires are joined and no change in programming is needed. 
     The airjet mover is an exemplar of a smart matter system. The airjets provide a low-mass system for moving objects in three degrees of freedom without making physical contact with the objects. 
     It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.