Summary of the invention
The objective of the invention is to overcome defective of the prior art, design a kind of high-precision dynamic mechanically hand cantilever weighing apparatus.
For achieving the above object, technical scheme of the present invention is to adopt a kind of manipulator cantilever weighing apparatus, comprise the vertical line guide rail, pull pressure sensor is equipped with in lower end at described vertical line guide rail, Sucking disc stand is equipped with in lower end in described pull pressure sensor, described Sucking disc stand constitutes object with air pump, reversal valve, pipeline and picks up releasing mechanism, and described pull pressure sensor is connected with the circuit board of weighing, and described vertical line guide rail matches with the horizontal linear guide rail; Described vertical line guide rail can be along horizontal linear guide rail left and right displacement, described pull pressure sensor, Sucking disc stand and picked up by Sucking disc stand or the object that discharges can be along the upper and lower displacement of vertical line guide rail, on described vertical line guide rail, down-feed screw is housed, described down-feed screw is connected with first servomotor by shaft coupling, described down-feed screw cooperates with vertical nut, described vertical nut is connected with an end of pull pressure sensor, the other end of described pull pressure sensor is connected with described Sucking disc stand, on described horizontal linear guide rail, horizontal screw lead is housed, described horizontal screw lead is connected with second servomotor by shaft coupling, described horizontal lead screw cooperates with horizontal nut, and described horizontal nut is connected with the vertical line guide rail.
Wherein, in the lower end of described Sucking disc stand several suction nozzles are housed, described suction nozzle is connected with described air pump through pipeline, reversal valve.
Wherein, described reversal valve is connected with the described circuit board of weighing, the commutation of the described circuit board may command reversal valve of weighing.
Wherein, described vertical line guide rail and described first servomotor are fixed on the L bracket.
Wherein, described horizontal linear guide rail and described second servomotor are fixed on the horizontal stand, and described horizontal stand also is connected with described L bracket.
Wherein, described pull pressure sensor is a S type pull pressure sensor.
Wherein, the described circuit board of weighing is installed in a side of described horizontal stand.
Wherein, in the described circuit board of weighing, be provided with pull pressure sensor signaling conversion circuit and digital signal processing algorithm circuit.
Advantage of the present invention and beneficial effect are: this manipulator cantilever weighing apparatus, owing to LOAD CELLS has been installed in the lower end of mobile mechanical arm, the handling process and the weighing process of object can be combined, the present invention can save time, obtain high precision (per mille, the perhaps gram level weight precision) gravimetric value of each object again fast.It is compared with traditional belt conveyer scale, and significant advantage is arranged on weighing precision.
Embodiment
Below in conjunction with drawings and Examples, the specific embodiment of the present invention is further described.Following examples only are used for technical scheme of the present invention more clearly is described, and can not limit protection scope of the present invention with this.
As attached illustrated in figures 1 and 2, the concrete technical scheme of implementing of the present invention is:
A kind of manipulator cantilever weighing apparatus, comprise vertical line guide rail 1, in the lower end of described vertical line guide rail 1 pull pressure sensor 2 is housed, in the lower end of described pull pressure sensor 2 Sucking disc stand 3 is housed, described Sucking disc stand 3 constitutes object 4 with air pump, reversal valve, pipeline and picks up releasing mechanism, described pull pressure sensor 2 is connected with the circuit board of weighing, and described vertical line guide rail 1 matches with horizontal linear guide rail 5; Described vertical line guide rail 1 can be along horizontal linear guide rail 5 left and right displacement, described pull pressure sensor 2, Sucking disc stand 3 and picked up by Sucking disc stand 3 or the object 4 that discharges can be along 1 upper and lower displacement of vertical line guide rail.
In the present embodiment, on described vertical line guide rail 1, down-feed screw 6 is housed, described down-feed screw 6 is connected with first servomotor 7 by shaft coupling, described down-feed screw 6 cooperates with vertical nut 8, described vertical nut 8 is connected with an end of pull pressure sensor 2, and the other end of described pull pressure sensor 2 is connected with described Sucking disc stand 3.
In the present embodiment, several suction nozzles 9 are housed in the lower end of described Sucking disc stand 3, described suction nozzle 9 is connected with described air pump through pipeline, reversal valve.
In the present embodiment, described reversal valve and the described circuit board of weighing are electrically connected, the commutation of the described circuit board may command reversal valve of weighing.
In the present embodiment, described vertical line guide rail 1 is fixed on the L bracket 10 with described first servomotor 7.
In the present embodiment, on described horizontal linear guide rail 5, horizontal screw lead 11 is housed, described horizontal screw lead 11 is connected with second servomotor 12 by shaft coupling, and described horizontal lead screw 11 cooperates with horizontal nut 13, and described horizontal nut 13 is connected with vertical line guide rail 1.
In the present embodiment, described horizontal linear guide rail 5 is fixed on the horizontal stand 14 with described second servomotor 12, and described horizontal stand 14 also is connected with described L bracket 10.
In the present embodiment, described pull pressure sensor 2 is a S type pull pressure sensor.
In the present embodiment, the described circuit board of weighing is installed in a side of described horizontal stand 14.
In the present embodiment, in the described circuit board of weighing, be provided with pull pressure sensor signaling conversion circuit and digital signal processing algorithm circuit.
In the present embodiment, have under the acceleration in order to reach, little weight, the high-precision purpose of weighing, the invention provides a kind of solution, in carrying object 4 processes, have a break, damping rocks under the situation and to throw a plurality of objects that will weigh 4 down successively, wherein said having a break is meant that vertical line guide rail 1 and appurtenances (vacuum cup frame etc.) thereof stop above horizontal linear guide rail 5 is transported to belt conveyor, stop between 0.5 second to 1 second, picked object 4 still is in low frequency and rocks state at this moment.After damping is rocked the sucker that is meant Sucking disc stand and is evacuated, object 4 has been picked up, meanwhile Sucking disc stand 3 shrinks, and object 4 is relied on the damping material (wrapped pad in vibration-absorptive material such as the packing case) around the Sucking disc stand 3.So in carrying/pause process, object 4 can be attached to 3 times bonding damping materials of Sucking disc stand and make the low frequency amount of decrease and rock.
It has reduced weighting error effectively, has saved handling time.Obtain full weight numerical value, loss of weight numerical value and bare weight numerical value successively respectively.After this series of values is made difference, and then obtain the gravimetric value of predictable each object of error range.For example carry 4 objects simultaneously, be parked on carrying belt when top, S type pull pressure sensor 2 numerical value of weighing is full weight numerical value, and promptly the weight of 4 objects adds the internal stress that Sucking disc stand weight and pipeline apply S type pull pressure sensor 2.Discharge 1 object 4 according to 0.5 second Sucking disc stand, in 2 seconds, all be discharged into the object 4 of carrying on the Sucking disc stand 3 on the belt conveyor and before being transported to the ccd video camera camera lens.Abandon 1 object, S type pull pressure sensor 2 is all measured a loss of weight numerical value so at every turn.After whole objects 4 all were put on the belt conveyor, Sucking disc stand 3 weight and pipeline were exactly bare weight numerical value to the internal stress sum of S type pull pressure sensor 2.The purpose that described columns value is made difference is the actual tested weight that obtains each object after utilizing the full weight numerical value, loss of weight numerical value and the bare weight numerical value that obtain above to subtract.This kind method not only can solve the above-mentioned difficult problem of weighing, and compact arranged object is carried out equally spaced loose arrangement along the belt conveyor system that turns round, and helps the processing of next operation.Described S type sensor is a type of pull pressure sensor.The shape of S type metallic steel/aluminium can produce symmetry deformation after bearing pressure, on the changing sensor that this deformation effect is pasted in inside, and be equipped with the full bridge measurement circuit, changes into electric signal output.Why S type pull pressure sensor is widely used and the cost performance height, is exactly that stress deformation symmetrically and evenly because electric signal output ratio is big.
The technical solution adopted for the present invention to solve the technical problems is: a S type pull pressure sensor 2 is installed under the Z-axis mechanical arm, object 4 (for example 4 groups) picks up releasing mechanism and the dynamic weighing circuit board in Z-axis mechanical arm side constitutes the subsystem of weighing.
S type pull pressure sensor is picked up releasing mechanism and is weighed together with object, object, promptly give pre-gravimetric value of this sensor (about more than 1 kilogram), avoided this sensor when a small amount of journey, because the mistake that the best input impedance of impedance output and dynamic weighing circuit does not match and causes, make and to measure the interlude of object weight combinations, utilize the middle Linearity of this sensor pressure-voltage signal curve best, input and output impedance matching the best to measure at this transducer range.This way makes the dynamic weighing circuit reduction, has realized effectively and rapid weighing.Eliminate frequent zero drift and stress wriggling, recovering S type pull pressure sensor weighing precision also is the problem that this invention is considered.
The method that is adopted is: this sensor is in state of tension at ordinary times, when object picks up releasing mechanism and has grasped many pieces of objects simultaneously, allow this sensor slightly transship, suffered pulling force reduces to zero, becomes pressure, eliminates the stress hysteresis of this sensor and cuts down the zero drift amount.Wherein, peacetime state, S type pull pressure sensor is because (weight are arranged) such as Sucking disc stands that the bottom hangs is in state of tension.Time has been grown so, drifts about certainly the zero point of S type pull pressure sensor and also slight deformation of S type pull pressure sensor, and Linearity has also changed influences measuring accuracy.Slight overload is exactly the vertical line guide rail movement, Suction cup assembly is placed on the absorbate spare, and applies a certain amount of pressure downwards.For S type pull pressure sensor, it is in pressure state so, promptly at first becomes the state of not stressing by state of tension, and then becomes pressure state.This pressure state is not more than the stressed upper limit of S type pull pressure sensor.Allow S type pull pressure sensor accept pulling force, this symmetric stressed sure reduction zero point drift amount of pressure regularly.Stress hysteresis shows that in fact more the regime of elastic deformation of S type metallic steel/aluminium diminishes, and uses said method also to recover its regime of elastic deformation effectively.
Pick up several objects, slinging to the belt conveyor position, adopting to discharge object successively along the belt movement direction, the electric signal that the subsystem of weighing is gathered S type pull pressure sensor obtains the weight difference through conversion.The method is used the counterweight rapid weighing method that subtracts of electronic balance, adds digital signal processing algorithm therein.The first, the error of object gravimetric value is rocked in its elimination, and second eliminates the error of sensor output signal.Send through the mode of the gravimetric value after the conversion, as the whether qualified foundation and the usefulness of file with digital communication.It is described that to subtract that counterweight weighs be that a kind of per mille gram weigh scale, weigh are fast arranged.Glass square box of its outer image, lower surface is a pallet, holds testee.Inside is that counterweight mechanism is placed/picked up to a cover.Before weighing began, pallet and weight group constituted a leverage.Weight group's default conditions are to be placed on lever one end.Testee is placed on the pallet, and inner placement/pick up counterweight mechanism to do operation by half promptly subtracts the counterweight of half weight down earlier, see greater than or less than tested weight.If greater than would then subtract the counterweight of half weight of being left down, whether see once more greater than still less than; Less than the counterweight that then adds remaining half weight.The rest may be inferred through counterweight weight just can be near the actual weight of measured object seldom several times.
Wherein, the method that the error of object gravimetric value is rocked in elimination is, at first S type pull pressure sensor is actual can only make stressed/weighing measurement to a direction, in fact the measurement of rocking weight of object can be broken down into making a concerted effort of above-mentioned direction and certain direction, seldom a part is relatively near actual stationary body weight after promptly rocking the measurement data of weight of object, and this is f (t)=e just
-atThe source of this classical formulas.In other words, the rolling animal body is the center of circle with the sucker, does the reciprocal damped motion of circular arc (amplitude is more and more littler of static) under Sucking disc stand, the stressed electric signal of S type pull pressure sensor output vertical direction.Its data characteristics curve infinitely approaches actual value.Because adopt the cause of damping Sucking disc stand, stop basically rocking in general 0.5 second.So we can be at the appointed time, obtain all and measure numerical value, sort, choose big numerical range, just there is the limit, there near the numerical value of actual weight; Obtain the gravimetric value that error allows after revising then.
The method of eliminating the error of sensor output signal is, the first, shorten S type pull pressure sensor wire length, and reduced by the chance of electromagnetic interference (EMI).The second, weigh circuit board and S type pull pressure sensor are placed nearby, and signal transmits with digital quantity with communication mode.The 3rd, the output weight/voltage table of the supporting S type of the circuit board of weighing sensor, intelligence eliminate stress sluggishness and zero point drift.
The present embodiment advantage is: the handling process and the weighing process of object can be combined, save time, obtain high precision (per mille, the perhaps gram level weight precision) gravimetric value of each object fast.It is compared with traditional belt conveyer scale, and significant advantage is arranged on weighing precision.Have under the acceleration in order to reach, little weight, the high-precision purpose of weighing, the invention provides a kind of solution, in carrying object process, have a break, damping rocks under the situation and to throw a plurality of objects that will weigh down successively, obtains full weight numerical value, loss of weight numerical value and bare weight numerical value successively respectively.After this series of values is made difference, and then obtain the gravimetric value of predictable each object of error range.This kind method not only can solve the above-mentioned difficult problem of weighing, and compact arranged object is carried out equally spaced loose arrangement along the belt conveyor system that turns round, and helps the processing of next operation.
The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the technology of the present invention principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.