Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/88—Sonar systems specially adapted for specific applications
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/06—Systems determining the position data of a target
  • G01S15/08—Systems for measuring distance only
  • G01S15/10—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves
  • G01S15/101—Particularities of the measurement of distance
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
  • G01S7/52004—Means for monitoring or calibrating
  • G01S7/52006—Means for monitoring or calibrating with provision for compensating the effects of temperature

Definitions

• This invention concerns a method and a device for measuring the volume of a loaf of bread.
• the baking results depend on the quality of the ingredients, espe- cially the flour, and on the baking process.
• the flour quality is often tested by baking bread according to a standardised baking test, for instance a test authorised by the American Association of Cereal Chemists or the International Association for Cereal Science and Techno- logy, and then measuring the volume of the resulting loaves of bread.
• the volume of a loaf of bread is usually determined by placing the loaf in a container of known volume, which then is filled with a calibrated amount of rape or poppy seed surrounding the loaf.
• the volume of the loaf can be read on a scale on the container, this scale being graduated as a function of the volume of the container and the calibrated amount of seed.
• FR-2,544,072 teaches an alternative method for mea ⁇ suring the volume of bread, in which a loaf of bread is placed on a rotary table and is illuminated from behind. A camera takes a silhouette picture of the loaf from a site diametrically opposite to the site from which the loaf is illuminated. Then, the loaf is rotated, and the measurement is repeated at a number of different angles of rotation. The volume of the loaf is determined by com ⁇ puter processing of the silhouette pictures, each sil- houette being divided into a number of segments, of which the lengths and the heights are used for determining the segment volume according to a given formula.
• EP 0 415 771 discloses a method for measuring the size of an object, in which three ultrasonic transducers measuring in three orthogonal directions determine the maximum length, the maximum width and the maximum height of the object. On the basis of these measurements, the volume of the object can be determined.
• this prior-art method for determining the volume of an object cannot be used on bread, since loaves of bread normally are of irregular shape and the EP method yields highly inaccurate volumetric values for such objects.
• EP 0 357 905 teaches a method and an apparatus for measuring the profile of an object.
• the measurement which is especially adapted to contact lenses, is performed under water and is thus unsuitable for bread.
• the object of this invention is to provide a new method and a new device for measuring the volume of a loaf of bread, which obviate the inconveniences of the prior art. This object is attained by a method and a device having the distinctive features recited in appended claims 1 and 6, respectively.
• Fig. 1 is a schematic side view of an embodiment of the inventive device for measuring the volume of a loaf of bread
• Fig. 2 is a schematic side view, partly in the form of a block diagram, which shows the device in Fig. 1 seen from another side.
• the volumenometer for bread illustrated in Figs 1 and 2 comprises a holder 1 for carrying a loaf of bread 2 (indicated by dash-dot lines in Fig. 2).
• the holder 1 which has the shape of a fork, is mounted in an attach ⁇ ment 3 rotatably mounted in a base 4.
• the attachment 3 can be removed, enabling the use of different holders for different loaves of bread.
• a first motor 5 is mounted on the base 4.
• the motor 5 has an output shaft 6, which may cause the attachment 3 to rotate by the intermediary of a belt 7.
• a frame 8 On the base 4, there is further provided a frame 8, on which is movably arranged an arm construction 9 having a first, vertical arm 9a and a second, transverse arm 9b.
• An ultrasonic transducer 10 is mounted at one end of the transverse arm 9b.
• the vertical arm 9a is formed with a groove 11, in which the transverse arm 9b can be fixed in different positions in order to adjust the height of the transducer 10 to different-sized loaves of bread.
• the ultrasonic transducer 10 comprises a transmit ⁇ ter and a receiver.
• the transmitter transmits a focused beam having a focal distance of, say, 10 cm.
• the operat ⁇ ing frequency may advantageously be in the range of 100-1000 kHz.
• a second motor 12 which has an output shaft 13 driving a belt 14, which in turn drives a shaft 15, which is mounted in the frame 8 and on which the arm construction 9 is mounted.
• the arm construction 9 is adapted to entrain the transducer 10 in a semicircular movement round a reference point R, which is the point of intersection of the longitudinal axis LI, about which the holder 1 is rotated, and the longitudinal axis L2, about which the arm construction 9 is pivoted.
• the transducer 10 is thus located at a constant distance from the reference point R during the entire movement.
• a first angle sensor 16 (illustrated schematically in the form of a block in Fig. 2) is mounted adjacent to the attachment 3 and is adapted to measure the angle of rotation of the holder 1.
• a second angle sensor 17 is mounted adjacent to the shaft 15 and is adapted to measure the pivoting angle of the arm construction 9.
• the two angle sensors are connected to a calculation means
• the ultrasonic transducer 10 is connected to the calculation means 18.
• a temperature sensor 21 for sensing the temperature at which the measurement is carried out.
• the temperature sensor 21 is connected to the calculation means 18 and disposed on the arm construction 9.
• the illustrated volumenometer for bread operates as follows. The loaf of bread 2, whose volume is to be mea ⁇ sured, is placed on the holder 1, and the height of the holder is adjusted such that the centre of the loaf is located approximately in the reference point R. Further, the transverse arm 9b is placed in a suitable position on the vertical arm 9a, and the distance from the transducer 10 to the reference point R is determined.
• the first and second motors 5 and 12 are started, such that the holder 1 carrying the loaf 2 is rotated about the longitudinal axis L2 at a constant angular velocity and that the arm construction 9 with the transducer 10 is pivoted about the longitudinal axis LI at a constant angular velocity.
• the angular velocity of the holder 1 is much higher than that of the arm con ⁇ struction 9.
• the calculation means 18 controls the ultrasonic transducer 10 in such a manner that the latter samples the distance to the surface of the loaf 2 at regular intervals.
• the ultrasonic transducer 10 transmits an ultrasound pulse towards the reference point R.
• the sound pulse is reflected by the surface of the loaf 2 back to the ultrasonic transducer 10.
• Being focused the sound pulse merely impinges upon a small area, for instance having a diameter of but a few milli ⁇ metres, on the surface of the loaf 2.
• the dis- tance from the transducer to the loaf is determined on the basis of the time it takes for the ultrasound pulse to travel from the transducer to the loaf and back again.
• the ambient temperature sensed by the temperature sensor 21 is taken into consideration, since the speed of propa- gation of the ultrasound pulse is temperature-dependent.
• the transducer 10 is pivot ⁇ ed approximately 170° about the reference point R, where ⁇ as the holder 1 is rotated a great many turns. In this manner, essentially the entire surface of the loaf will be successively scanned by pulses from the transducer 10 during one measurement, and a large number of distance values will be obtained.
• the angle of rotation of the holder 1 is determined by means of the first angle sensor 16, and the pivoting angle of the arm construction 9 is determined by means of the second angle sensor 17.
• the angle values are supplied to the calcula ⁇ tion means 18 in the form of input signals.
• the volume of the loaf of bread is calculated by the calculation means 18 as follows. For each sampling by the ultrasonic transducer 10, a corresponding distance to the surface of the loaf is determined. Each distance corre ⁇ sponds to a measuring point, whose coordinates are given by the angle values of the angle sensors 16 and 17. Each thus-determined distance to the surface of the loaf is subtracted from the known distance between the transducer 10 and the reference point R, so that one radius of the loaf is obtained for each measuring point.
• a part volume is then determined on the basis of the corresponding loaf radius, the dispersion of the ultrasound pulses, and the angle of rotation of the holder.
• the total volume of the loaf is obtained by add ⁇ ing up the part volumes, and the result is displayed on the display 20.
• the relative surface angular velocity between the transducer 10 and the loaf of bread will vary according to the pivoting angle of the arm con ⁇ struction 9, which is compensated for by weighting each part volume with the aid of the corresponding angle of rotation of the holder 1.
• the inventive volumenometer for bread All the inconveniences associated with the prior art are obviated by the inventive volumenometer for bread.
• the measurement is performed automatically, and the mea- suring results are stored directly in a computer.
• the measurement has high accuracy and repeatability. Being focused, the signal from the transducer merely impinges upon a small area in each sampling, and since essentially the entire surface of the loaf is scanned, the device is able to "see" the shape of the loaf, including its concavities, in every detail.
• the ultrasonic transducer in these contexts is advantageous, since the transducer is insensitive to dust, which is plentiful in bakeries and mills where the volumenometer is to be used. Furthermore, the ultrasonic transducer is insensitive to variations in colour of the bread surface. Finally, the transducer is able to accu ⁇ rately measure distances within a fairly large range, which is of great importance in the illustrated embodi- ment, where it is located at varying distances from the loaf of bread.
• the transducer and the loaf need not be displaced in the manner indicated above in relation to each other.
• the transducer may be stationary, and the loaf of bread may be rotated in the manner described above while being displaced in the vertical direction.
• the transducer and the loaf of bread are so displaced in relation to each other that essentially the entire surface of the loaf is scanned by means of a measuring signal from the trans ⁇ ducer, and that the distance between the transducer and a reference point in the loaf is known.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• General Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Computer Networks & Wireless Communication (AREA)
• Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
• Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20393005

Family Applications (1)

Country Status (2)

Cited By (3)

Citations (4)

• 1994
  • 1994-02-21 SE SE9400571A patent/SE504557C2/sv not_active IP Right Cessation
• 1995
  • 1995-02-21 WO PCT/SE1995/000176 patent/WO1995022744A1/en active Application Filing

Patent Citations (4)

Non-Patent Citations (1)

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