Method and apparatus for analysing automatically the physico-chemical parameters of a sample of fruits or the like.

0001The subject of the present invention is a method for automatically analyzing the physicochemical parameters on a fruit sampling or the like, and a unit for implementing said method.

0002The technical sector of the invention is that of processes and devices comprising laboratory apparatus for the analysis of the organoleptic qualities of products intended for human consumption.

0003Such analyzes are sometimes carried out in packaging stations manually and empirically. A machine is also known for testing fruits in order to measure their sugar content. Such a machine is described in the FR patent. 2,528,332.

0004The objective of the present invention is to determine on a sampling batch the organoleptic particularities of the fruits or the like, with a view to assessing them: the taste quality, the possibilities of conservation, the aptitude for industrial processing.

0005This objective is achieved by the method according to the invention for automatically analyzing the physico-chemical parameters on a fruit sampling or the like, by means of a robotic unit comprising a programmable automaton which is connected to a computer, characterized by the following steps:<ul id="ul0001" list-style="none"><li>a) the fruits of a sampling batch are received on receiving means with step-by-step scrolling;</li><li>b) each fruit of said sampling is weighed and the weight measurements are entered into the memory of said computer;</li><li>c) measuring the hardness of said fruits and entering said measurements in the memory of said computer;</li><li>d) extracting the juice of said fruits from the sampling;</li><li>e) the sugar content in said fruits is measured by means of an electronic refractometer and these measurements are entered in the memory of said computer;</li><li>f) collecting all the juice previously extracted;</li><li>g) all of the extracted juice is weighed and this measurement is entered into the memory of said computer;</li><li>h) a part of said extracted juice is collected in parallel with step f);</li><li>i) the acidity of said part of the juice extracted from the sampling batch is measured by acid-base reaction and this measurement is entered into the memory of said computer;</li></ul>    which computer gives the results of the analysis and the organoleptic qualities of the fruits including:<ul id="ul0002" list-style="dash"><li>The report<maths id="math0001"><math display="block"><mrow><mfrac><mrow><mtext>total fruit weight</mtext></mrow><mrow><mtext>total weight of juice extracted,</mtext></mrow></mfrac></mrow></math><img file="EP0572341A2_D0001.tif" /></maths></li><li>the individual and average hardness of the fruits as well as the standard deviations,</li><li>the individual and average sugar level as well as the standard deviations,</li><li>the average acidity of the fruit.</li></ul>

0006The objective is also achieved by the robotic unit according to the invention, for the analysis of the physico-chemical parameters of a fruit sampling or the like, comprising a programmable automaton connected to a computer and means for controlling the necessary energies. in the operation of said unit, characterized in that it comprises in combination:<ul id="ul0003" list-style="none"><li>a) means for receiving step by step the fruits of a sampling batch;</li><li>b) means for weighing each fruit of said sampling;</li><li>c) means for measuring the hardness of said fruits;</li><li>d) means for extracting the juice from said fruits;</li><li>e) means for measuring the sugar content of the extracted juice;</li><li>f) means for collecting all the juice extracted;</li><li>g) means for weighing all the juice extracted;</li><li>h) means for collecting part of said extracted juice;</li><li>i) means for measuring the acidity of said part of the juice extracted from the sampling batch and in that the measurements carried out in b), c), e), g) and i) are entered in the memory of said computer, which compares said measurements and the parameters entered in its memory and gives the results of the analysis and the organoleptic qualities of the fruits:</li></ul><ul id="ul0004" list-style="dash"><li>The report<maths id="math0002"><math display="block"><mrow><mfrac><mrow><mtext>total fruit weight</mtext></mrow><mrow><mtext>total weight of the extracted juice,</mtext></mrow></mfrac></mrow></math><img file="EP0572341A2_D0002.tif" /></maths></li><li>the average hardness of the fruit,</li><li>the average sugar level,</li><li>the average acidity of the fruit.</li></ul>

0007Said unit comprises a frame and means for controlling the energies necessary for its operation, and further comprises a substantially horizontal plate, mounted for rotation on said frame and comprising circular orifices regularly distributed around the perimeter of the plate, which is driven sequentially by a gear motor, by fraction of a turn corresponding to the arc which separates two orifices, which are of a diameter smaller than that of the fruits, so that the fruits placed on said tray remain partially engaged in said orifices awaiting their analysis.

0008In a preferred embodiment, said plate adopts an annular shape and is mounted to rotate on rollers mounted for free rotation, on said frame, which plate is subjected to the action of centering rollers bearing on its peripheral edge and its drive in rotation is produced by a friction roller subjected to the action of elastic means and wedged on the output shaft of said sequential geared motor.

0009Said plate comprises a detector for the presence of the orifices, associated with a retractable stop finger situated in the path of said orifices, which finger is of a section smaller than that of said holes, in order to penetrate therein and sequentially stop the plate. in a specific position.

0010Said means for weighing each fruit consists of a fruit presence detector, associated with a retractable cup with a diameter smaller than that of the orifices of the tray, and located on the path of said orifices, which cup is carried by a force connected to said computer and is subjected to the action of means to make it penetrate into said orifices, in order to lift sequentially and in synchronism with the operation of the tray a fruit of sampling for its weighing.

0011Said means for measuring the hardness of the fruits, consist of means for immobilizing each fruit sequentially in synchronism with the other organs of the unit, and a penetrometer coupled to a force sensor, connected to said computer, the punch of which is actuated in synchronism to penetrate the fruit.

0012In a preferred embodiment, said means for measuring the hardness of the fruits consist of a first fixed cup secured to the frame, located above the plate and on the path of the orifices, to the right of which the orifices successively immobilize of the plate and a second retractable cup, coaxial with said first cup, the concavities of said cups are opposite; said second cup is of a diameter smaller than that of said orifices and is actuated by telescopic means located below said plate, to make it pass through said orifices in turn and bring the fruit, whatever its size, resting on said first cup, which has a central hole through which the punch of the penetrometer passes.

0013Said unit comprises in line with the axis of the penetrometer a fruit ejector having passed the hardness measurement station, which ejector is parallel to said plate and is located between said plate and said first fixed cup of the penetrometer.

0014In one embodiment, said telescopic means of the second cup consist of two superimposed jacks, one of which has the function of moving said cup to put the fruit in abutment on said first fixed cup, and the other of which has for the function of temporarily immobilizing the cup above said tray, to put the fruit substantially within the field of action of said ejector and to transfer the fruit: from said tray to said means for extracting the juice.

0015Advantageously, the end of the penetrometer's punch has a concavity delimited by a sharp peripheral edge, for cutting the skin of the fruit before the punch penetrates into the flesh of the fruit.

0016Said means for extracting fruit juice consist of a press, arranged substantially horizontally and below said tray, which press has a lateral orifice for receiving the fruits ejected from the tray.

0017In one embodiment, said press consists of a cylinder open at its ends, the wall of which has an opening for the introduction of fruit by gravity, in which cylinder is mounted a piston fixed to the movable rod of a double-acting cylinder, the body of which is fixed to the frame to move the piston along the length of said cylinder, which cylinder is coupled to the movable rod of a double-acting cylinder, whose body is fixed to the frame and whose rod has the function of pressing the cylinder against an anvil fixed to said frame, and to move it away from it, in order to drop by gravity the dry matter of the fruit after extraction of the juice, under the pressure exerted by said piston on the fruit in abutment on the anvil, to which anvil is fixed a tubing for draining the juice.

0018The juice from said anvil is channeled through a first tube to pass through a refractometer in order to measure the sugar level, and then bring the juice into a receiving tank called total collection. The unit further comprises upstream of said refractometer a tee, the main tube of which is connected to said first tube is inclined downstream towards the refractometer and the branch tube of which is located below said main tube and connected to a second tube leading to a second receiving tank known as a partial collection tank, which second tube comprises a first valve located on the side of said tee for collecting, in the closed position of the valve, a sample of the juice from each fruit in the batch and a second valve located downstream of said first valve for collecting, in the closed position of said second valve, all of the samples of the fruit juice from a sampling batch.

0019The tanks for receiving the total harvest and the partial harvest are each carried by a force sensor fixed to said frame and connected to said computer.

0020Said unit further comprises a tubing from the reserve of a base and terminating in said second partial collection reception tank, on which tubing is inserted a valve connected to control means for delivering doses from said base into said tank ; an agitator and a pH probe connected to said computer.

0021Said base metering valve, said agitator and said probe are mounted on a vertically movable arm actuated by a double-acting cylinder, to immerse the probe and the agitator in said partial collection tank or to extract them from said tank, to allow the removal of the total and partial harvest bins for periodic cleaning.

0022The result of the invention is the determination of the organoleptic particularities of the fruits or the like, for the application of said process implemented by the aforementioned robotic unit.

0023The proposed equipment makes it possible to generalize the analyzes of the physicochemical parameters over a sampling batch, in a rigorous and economical manner. All operations are controlled by computer, which also performs all the calculations and analysis of the results.

0024Other advantages and characteristics of the invention will become apparent on reading the following description given by way of nonlimiting example and with reference to the accompanying drawings, in which:<ul id="ul0005" list-style="dash"><li>FIG. 1 is a schematic perspective view of a unit according to the invention,</li><li>FIG. 2 is a partial schematic perspective view of the rotating annular table and of the means for measuring the hardness of the fruit, the pressing means and the sampling point for the juice,</li><li>FIG. 2a is a sectional view of the end of the punch of the penetrometer,</li><li>FIG. 3 is a partial schematic perspective view of the annular table and of its means for stopping and weighing the fruit,</li><li>FIG. 4 is a partial schematic perspective view of the part of the unit which automatically measures the acidity and which comprises the partial collection and total collection reception tanks,</li><li>FIG. 5 is a diagram of the operation of said unit.</li></ul>

0025The robotic unit, as shown diagrammatically in FIG. 1, consists of a frame 1 mounted on rollers lc, comprising a computer cabinet 1a in which a computer 2 is placed, above it a keyboard 3 and a printer 4, and above the printer, a screen 5. Adjacent to this cabinet is a structure 1b which can form an enclosure and in which are mounted the apparatuses for analyzing the fruit and the power means of the unit. At the opposite end of the cabinet 1a and at the lower front part, there is a programmable controller and an electrical control module 6. At the same level and at the rear, a pneumatic control module 7. In the located part between said modules 6/7 and the cabinet 1a, an electronic refractometer 8 and its electronic module 9 are mounted, which cabinet also includes the electronics of the various force sensors that the robotic unit includes and which will be described below. Between the refractometer 8 and its module 9, is disposed a soda tank 10 connected to an "acidity" module 11, located at the lower part of the cabinet 1a, below the computer 2. This module will be described in detail later. Below the soda tank 10, is placed a bin 12 into which fall, by gravity, the dry waste of the fruits previously pressed to extract the juice and the washing effluents.

0026Above the part 1b of the frame, there is mounted for rotation a substantially horizontal annular plate 13, comprising receiving means for placing therein the samples of a batch of fruit, for example between twenty and thirty fruits.

0027Referring now to Figures 2 to 4 which show in more detail the different organs that make up the equipment of the robotic unit. The fruits are placed manually on said annular plate 13, which comprises said receiving means constituted by holes 13a regularly distributed in a pitch. These holes 13a are of a diameter slightly smaller than that of the smallest fruits to be analyzed, for example their diameter is equal to fifty millimeters. Said plate 13 is mounted to rotate on carrier rollers 14, for example three in number, and is held in place by centralizing rollers 15, for example three in number, one of which 15a is wedged on the outlet axis a gear motor 16 pushed by a spring 17 on the side of the plate and which ensures the slow rotation of the latter. To synchronize the rotation and stopping of the plate 13 with the other sequences of the process, the plate includes a detection and locking device in a precise position. These fixed position detection and blocking means are for example composed of an optical detector of the reflex type 18, located on the path of the holes 13a and above the plate 13, the reflector 18a of which is fixed to the end d 'a blocking lock 19, located coaxially with said detector and below said plate. Said latch 19 is fixed to the end of the movable rod 20a of a double-acting cylinder 20 which has the function of clearing the latch when the plate turns by a fraction of a turn, or by one step, and by make it penetrate into a hole 13a to immobilize the plate in a precise position. This latch 19 has a diameter smaller than that of the holes 13a and operates in synchronism with said detector 18. The electrical supply to the gear motor 16 is cut in synchronism with said detector 18 and with a slight delay, so that the inner edge of the hole 13a comes at the end of its travel in contact with the latch 19.

0028The weighing of the fruits placed on said tray 13 is carried out by a force sensor 21 on which is mounted, at one end, a cup 22, the force sensor 21 is fixed at its other end to the movable rod 23a of a jack double-acting 23. This assembly is located below the plate 13, so that the detection / blocking device 18/19 is downstream of said weighing means 21/22 relative to the direction of rotation F. The cup 22 is located on the path of the holes 13a. Above the plate 13 and coaxial with said cup 22, is mounted a sensor for detecting the presence of fruit 24, for example an optical detector of the reflex type, the reflector 24a of which is fixed in the bottom of the cup 22.

0029When the sensor 24 detects a fruit, the blocking latch 19 stops the plate 13 in a fixed position. The jack 23 is actuated and the cup 22 coming into contact with the fruit lifts it. The cup 22 is of a diameter smaller than that of the holes 13a of the plate, to pass through said holes during this operation. The fruit being separated from the tray is then weighed. After stabilization of the output signal from the force sensor 21, the weight measurement is entered in the memory of said computer 2. The jack goes down again, the fruit is again replaced in the hole 13a of the tray. The locking bolt 19 is then retracted below the plate 13 and the gear motor 16 is excited to rotate said plate a fraction of a turn, to put the next fruit in the field of the presence detector 24 / 24a.

0030The weight measurements of each fruit are memorized then their sum is calculated at the end of the batch. The 18/24 detectors can of course be of any known type, such as optical, capacitive or other.

0031The hardness measurement of the fruit is carried out in the next step in synchronism with the weighing of the fruit from the previous station. The hardness of the fruits 25 is measured by means of a penetrometer 26 located on the path of the holes 13a and on a perpendicular axis of the plate 13.

0032Said penetrometer 26 consists of a punch 27 whose end 27a (FIG. 2a) forms a concavity delimited by a circular cutting edge 27a₁, the function of which is to cut the skin of the fruit before entering the flesh. Said punch 27 is located above the plate 13 and is fixed to the end of a force sensor 28, itself fixed to the movable rod 29a of a double-acting cylinder 29, which punch is slidably mounted in a hole 30a of a cup 30 for centering the fruit 25, integral with the frame 1 of the robotic unit.

0033Said punch 27 is coaxial with a movable cup 31, of a diameter smaller than that of the holes 13a of the plate 13. The movable cup 31 is located below said plate 13 and is mounted on the movable rod 32a of a jack to double effect 32, itself actuated by a second cylinder 33 with a reduced stroke.

0034The jack 32 is fixed to the end of the movable rod 33a of said jack 33.

0035The two concave faces facing the cups 30/31 make it possible to center the fruit on the axis of the punch 27 of the penetrometer 26.

0036The fruit hardness measurement process is as follows:

0037After being weighed, the fruit 25 wedged in the hole 13a of the plate 13, is in synchronism with the preceding phases vertically from the penetrometer 26. The locking bolt 19 stops the plate 13. The jack 32 is actuated, the fruit 25 is lifted by the lower cup 31, until it is brought into contact with the fixed upper cup 30. It remains inserted between the two cups 30/31 all the time of the hardness measurement.

0038The upper cylinder 29 is actuated to lower the punch 27 and make it penetrate into the fruit 25 under a constant thrust and depth.

0039During the penetration of the punch 27 into the fruit, the force sensor 28 measures the force with which the flesh of the fruit opposes the penetration and this force is memorized in the computer 2. The hardness of the fruit is then deduced therefrom. comparison of the force stored and of parameters stored in the computer memory 2. Their average is calculated at the end of the sampling batch.

0040After memorizing the hardness measurement, the upper 29 and lower 32 cylinders are returned to their initial rest position.

0041The unit comprises, in line with the axis on which the punch 27 of the penetrometer moves, an ejector 34 of the fruit 25 having just been tested.

0042Said ejector 34 consists of a double-acting cylinder 34a disposed horizontally, parallel to the plate 13, the movable rod of which carries a push pallet 34b.

0043After memorizing the hardness measurement and after the jacks 32/29 are returned to their initial position, the jack 33 is actuated to keep the fruit above the plate 13.

0044The ejector cylinder 34 is actuated and the fruit is ejected inside the annular plate towards means for extracting the juice from the fruit. Said means consist of a press 35 disposed horizontally below the plate 13 and comprising a cylinder 36 open at its two ends and comprising a lateral opening 36a reserved in its wall. This opening 36a is located at the part of the cylinder closest to the plate 13. The internal diameter of the cylinder 36 and the diameter of said opening 36a are greater than that of the largest fruits to be analyzed.

0045The fruits 25 from the plate 13 and ejected by the device 34 fall by gravity into said cylinder, passing through the lateral opening 36a.

0046In said cylinder 36 moves a piston 37, fixed to the movable rod 38a of a double-acting cylinder 38. Said cylinder 38 is coaxial with the cylinder 36 and mounted integral with the frame by any known means. Its open end 36b located opposite said cylinder 38 is opposite an anvil 39, for example cylindrical, which is coaxial with said cylinder 36, and mounted to the frame of the robot unit.

0047Said press 35 comprises means for bringing the cylinder 36 closer or further away from the anvil 39. These means consist of a double-acting cylinder 40 fixed to said frame and arranged parallel and below the cylinder 36. Its movable rod is connected to a tab 36c fixed near the open end 36b and opposite the opening 36a.

0048The anvil 39 forms a bowl on its face located opposite the cylinder 36 and comprises at its lowest point an orifice to which a juice collecting tube 41 is connected.

0049In the initial position of the press, the rod of the cylinder 40 cylinder is extended and that of the cylinder 38 is retracted. Under these conditions, said cylinder 36 is closed by pressing on the anvil 39. The opening 36a is free to receive a fruit.

0050After having undergone the hardness measurement, the fruit 25 is ejected from the plate 13 and falls by gravity into the cylinder 36 through said opening 36a. The piston cylinder 38 is actuated, the fruit 25 is moved by the piston 37, to the anvil 39 and is then crushed between said piston and the anvil.

0051The juice resulting from this pressure flows through the collecting tube 41. After the time necessary for the total extraction of the juice, the cylinder cylinder 40 is actuated simultaneously with the piston cylinder 38. The two rods of the cylinders 38/40 are returned, the cylinder 36 moves away from the anvil 39 and the dry matter of the crushed fruit 25a falls by gravity into the bin 12.

0052The jack 40 is then actuated and puts the cylinder 36 back on the anvil 39 awaiting the next fruit.

0053The sugar level of each fruit is measured during the flow of its extracted juice by means of the press 35. The tube 41 is inclined and the juice from the anvil 39 flows by gravity through a refractometer 42, until to the acidity measurement means which will be described later.

0054The measurements of the sugar level of each fruit are memorized, then their average is calculated at the end of the sampling batch.

0055The definition of the report<maths id="math0003"><math display="block"><mrow><mfrac><mrow><mtext>total fruit weight</mtext></mrow><mrow><mtext>total weight of juice</mtext></mrow></mfrac></mrow></math><img file="EP0572341A2_D0003.tif" /></maths> requires total collection of the extracted juice. The acidity measurement requires a partial collection of the juice of each fruit to limit the consumption of soda and the analysis time.

0056To carry out these measurements, the unit comprises an inclined tee 43, for example at 45 °, whose main tube 43a is connected by its ends to two sections of said tube 41 and whose bypass tube 43b which is located below of said main tube 43a, is connected to a second flexible tube 44, terminating above a partial collection tank 45 (FIG. 4).

0057The juice from the refractometer 42 flows through a tube 46 and is collected in another reception tank 47 (FIG. 4), called the total collection tank.

0058Downstream of the tee 43 is mounted a solenoid valve 48 of the tube pinch type. Downstream of said solenoid valve 48, the tubing 44 is wound in a spiral 44a, for example forming three turns.

0059Downstream of said spiral, the tubing 44 comprises a second solenoid valve 49 identical to that 48 mentioned above. The spiral 44a constitutes a reserve of juice, when the solenoid valve 49 is closed.

0060Initially, the solenoid valves 48/49 are closed. The fruit juice extracted by the press 35 flows by gravity through the main tube 43a of the tee and fills the bypass tube 43b and the section of the tubing 44 closed by the solenoid valve 48, then the overflow flows through the refractometer 42 to the vat 47 audit.

0061At the end of the juice extraction, the solenoid valve 48 is open and the quantity of juice contained in the bypass tube 43b and the tube section 44 flows into the reserve of juice that constitutes the spiral 44a.

0062The solenoid valve 48 is closed until the next fruit. At the end of the sampling batch, the total collection tank 47 contains almost all of the juice. The solenoid valve 49 is then opened to pour into the partial collection tank 45 all of the juice contained in the spiral 44a and representing the sum of the calibrated samples of each fruit of said batch.

0063The different stations operating simultaneously, the juice reserve device makes it possible to measure the acidity of the batch in progress, while a new batch is introduced into the unit, for the measurement of the hardness weight. sugar level ...

0064The total weight of juice is equal to the sum of the weights of juice in the two tanks for partial harvest 45 and total harvest 47.

0065Weight measurements are made using force sensors 50/51.

0066The tank 45 is mounted on a support 52 fixed to the free end of the force sensor 50, which is fixed by its other end to the frame 1b. The tank 47 is mounted on a support frame 53 fixed to the free end of the force sensor 51, the other end of which is fixed to said frame 1b.

0067For the measurement of acidity, the principle used is titration by acid-base reaction. The base used is diluted soda.

0068The automatic titration device is carried by an arm 54 vertically movable by means of a double-acting cylinder 55 fixed to the frame 1b and whose movable rod 55a is fixed to a tab 54a integral with said arm. It is of course guided in vertical translation by slide means (not shown). It comprises a first support plate 56 extending horizontally and on which is mounted a gear motor 57 on the output shaft of which is fixed the axis 58a of a stirrer 58 arranged vertically.

0069The plate 56 also carries a tube pinch solenoid valve 59, the tube 60 of which is connected on the one hand, to a reserve of soda (not shown) and on the other hand, at its lower end 60a located below the plate 56 and opposite the partial reception tank 45.

0070The arm 54 further comprises a vertical extension 54b extending downwards, at the end of which is fixed a second plate 61 parallel to said plate 56. This second plate 61 carries a soda of Ph 62, extending vertically and parallel to the axis of the agitator 58.

0071The tube 60 for the arrival of the soda and the tube 44 for partial collection terminate at this plate and slightly exceed it from below.

0072This suction plate also leads to a suction tube 63, for emptying the tank 45 at the end of the analysis of a batch and another suction tube 64, for emptying the total harvesting tank 47.

0073The axis of the agitator 58 crosses the plate 61. The agitator 58, the Ph probe 62 and the tubes 44/60/63 are grouped together to appear above the receiving tank 45. In the retracted position of the rod 55a of the jack 55, the arm 54 is lowered and the said tubes 44/60/63, the probe 62 and the agitator 58 are introduced into the container 45. At the same time, the suction tube 64 is introduced into the collecting tank total 47.

0074In the extended position of the rod 55a of said jack, the arm stops in the high position, which has the effect of allowing the two trays 45/47 to be manually released, to ensure cleaning at the end of the day.

0075During the measurements, the arm 54 is in the low position, the jack rod 55 is retracted.

0076Throughout the duration of extraction of the fruit juice, the solenoid valve 59 is closed, and the agitator 58 is stopped.

0077When the sampling of the juice is finished, the content of the spiral 44a having been emptied into the partial reception tank 45, the weight of the juice is measured by the force sensor 50, then stored. The agitator is started and the Ph is measured by means of the probe 62 then memorized after stabilization of the measurement. The sodium hydroxide valve 59 is then opened until the value of Ph reaches a predetermined threshold and stored in the computer 2, for example Ph = 6.

0078At Ph = 6, the opening of the solenoid valve 59 is modulated at an increasingly low rate, as the Ph increases.

0079At Ph = 8.2 for example, the solenoid valve 59 is closed. The weight of the solution is then again measured by means of the force sensor 50, then stored. The agitator 58 is stopped. The acidity is calculated according to the initial weight of the juice and the amount of soda added to obtain Ph 8.2 (value corresponding to the equivalence of the acid-base reaction).

0080At the end of the measurement, the two tanks 45/47 are emptied by suction by means of the tubes 63/64, which are connected to a convergent / divergent venturi (not shown).

0081At the end of the sampling batch, the computer analyzes the various parameters, such as the refractive index, the hardness, the acidity, the weight / juice ratio, in order to assess:<ul id="ul0006" list-style="dash"><li>taste quality,</li><li>conservation possibilities,</li><li>aptitude for industrial processing (fruit juice, fruit in syrup, jams, etc.).</li></ul>

0082The operating diagram of the unit is given in Figure 5 in the form of a block diagram.

0083The different stations of the robotic unit operate in successive simultaneous phases. Thus, after weighing the first fruit, the next fruit is weighed during the hardness measurement of the previous fruit. The weighing of the third fruit is carried out during the hardness measurement of the second fruit, simultaneously with the pressure of the first fruit, with a view to extracting the juice from it, etc.

0084The acidity measurement is carried out during the previous phases.

0085The diagram in FIG. 5 gives the operation of the robotic unit according to the invention.

0086The fruits of a sampling lot are selected and placed on the annular plate 13 at 65.

0087In 66, rotation of the tray in order to bring the first fruit to the weighing station.

0088In 67, the plate being always in rotation, wait until the condition: "the first fruit is weighed" is fulfilled.

0089In 68, weighing the first fruit.

0090In 69, rotation of the plateau.

0091In 70, the plate being in rotation, wait until the condition: "first fruit under the penetrometer 26" is fulfilled.

0092In 71-72 weighing of the second fruit simultaneously with the measurement of the hardness of the first fruit or weighing of the N + 1 fruit and measurement of the hardness of the Nth fruit.

0093In 73, ejection of the 1st or the Nth fruit

0094In 74, wait until the condition: "Nth pressed fruit + N + 1 weighed fruit" is fulfilled.

0095In 75, the Nth fruit is pressed. Take a dose of juice and temporarily store it in the spiral reserve 44a.

0096Parallel to step 75, in 76 rotation of the annular plate 13.

0097In 81-77, wait until one of the two conditions: "N + 1 fruit under the penetrometer" (81) and "End of batch" (77) is achieved.<ul id="ul0007" list-style="dash"><li>If (81) is performed, the cycle loops back to steps 71 and 72 to process the following fruits.</li><li>If (77) is carried out, that is to say that the N + 1 fruit was the last of the batch and that the operator sent the order "End of batch" via the computer, the cycle is diverted to step 78.</li></ul>

0098In 82, measurement of the sugar level of the juice of the Nth fruit.

0099In 83, rinsing of the acidity device at the end of step 80.

0100Of course, without departing from the scope of the invention, the parts which have just been described by way of example, may be replaced by a person skilled in the art by equivalent parts fulfilling the same function.