WO2007025810A1

WO2007025810A1 - Distance measuring device

Info

Publication number: WO2007025810A1
Application number: PCT/EP2006/064579
Authority: WO
Inventors: Uwe Skultety-Betz; Bjoern Haase; Joerg Stierle; Peter Wolf; Kai Renz; Clemens Schulte
Original assignee: Robert Bosch Gmbh
Priority date: 2005-09-01
Filing date: 2006-07-24
Publication date: 2007-03-08
Also published as: EP1924870A1; DE102005041475A1

Abstract

The invention relates to a distance measuring device, in particular, a laser distance measuring device (10) in the form of a portable device, comprising a path (28, 116, 122) for a measuring signal, a means (30, 52, 70, 92) for processing the measuring signal and an adjuster (32) for moving the means (30, 52, 70, 92). According to the invention, the adjuster (32) comprises an electromechanical element (38, 56, 78, 80, 94, 96, 98).

Description

23. 08. 05

ROBERT BOSCH GMBH; D-70442 Stuttgart

Distance measuring Equipment

State of the art

The invention is based on a distance measuring device, in particular a laser distance measuring device designed as a handheld device, according to the preamble of claim 1.

From DE 103 14 772 Al a distance measuring device is known with an optical mirror and an adjusting device for adjusting the optical mirror, which comprises adjusting pins designed as threaded pins. By screwing the alignment pins, a mirror support, to which the optical mirror is attached, can be adjusted, wherein the optical mirror can be adjusted in an optical path for a measurement signal.

Advantages of the invention

The invention is based on a distance measuring device, in particular a laser distance measuring device designed as a handheld device, with a path for a measuring signal, a means for processing the measuring signal and an adjusting unit for moving the means.

It is proposed that the adjustment unit has an electro-mechanical element. As a result, a tool-free movement of the means and, in addition, a compact construction of the adjustment unit can advantageously be achieved. The measurement signal can advantageously be designed as an optical signal. An alternative embodiment of the measurement signal as a radar or infrared radiation, an acoustic signal or an ultrasonic wave is also conceivable. In the processing of the measurement signal, the measurement signal may be from the means e.g. be redirected, divided and / or dampened or absorbed. If the measurement signal is an optical signal, the means may advantageously be designed as an optical deflection means, such as e.g. as a light reflecting means, as a lens, as a beam splitter, etc. Alternatively, the means of other optical signal processing elements, such as e.g. a shutter, a funnel, a collimator, etc., be formed.

It is also proposed that the adjusting unit is provided for adjusting the means. As a result, fine positioning of the agent can be advantageously carried out in positions suitable for a measurement. By way of example, the measuring signal may have a desired shape for a measurement after an adjustment of the means, for example a desired collimated or focused form. If the means is designed as a deflection means, the measurement signal can be precisely aligned in a desired direction. In a further embodiment of the invention it is proposed that the electromechanical element is provided for deformation and for moving the means by the deformation. As a result, movements of the agent can be carried out particularly precisely over small distances, which is particularly suitable for fine adjustment of the agent.

If the electromechanical element is a piezoelectric element, a compact and inexpensive construction of the adjusting unit can be achieved. The piezoelectric element may be formed by a piezoelectric crystal or by a piezoelectric ceramic.

Advantageously, the distance measuring device comprises a deformation element provided for supporting the means, which is provided for a deformation by the electromechanical element. Thereby, a small number of moving parts for moving the means can advantageously be achieved, since the movement of the means can be generated directly from the carrier element supporting the means. If the electromechanical element itself is intended for deformation, the electromechanical element may be directly attached to the support element, e.g. with a contact surface, be attached.

It is also proposed that the carrier element is drivable for a lever movement through the electromechanical element. As a result, it is possible to achieve movement of the agent over long distances with low energy consumption. The carrier element can advantageously be designed as a rod-shaped element. - A -

It is also proposed that the means is carried by a support surface of the support member and the support member is provided for deformation in at least two directions of the support surface. It can be achieved by the support surface advantageous stability of the agent. By deformation in several directions of the support surface, a multi-dimensional adjustment, e.g. an adjustment can be achieved.

A further embodiment of the invention provides that the means for deformation by the electromechanical element is provided. As a result, fine movements of the agent can be performed very precisely. If the electromechanical element itself is intended to be deformed, the means may advantageously be applied directly to the electromechanical means, e.g. with a contact surface, be attached. As a result, the electromechanical element can be formed as a carrier element.

In a further embodiment variant of the invention, the means is carried by at least one leg-shaped element having the electromechanical element. As a result, translational movements of the agent can be achieved particularly precisely on short distances. When the means is supported by at least two leg-shaped members, the leg-shaped members each having an electromechanical element, increased flexibility in positioning of the means can be achieved. The leg-shaped element is preferably formed by an elongate element. This is advantageously provided with a contact surface, which is expediently transverse to the longitudinal direction of the elongated egg. ment is attached to a support member for supporting the agent or directly to the means.

In an advantageous development of the invention, it is proposed that the distance measuring device has a control unit for controlling the electromechanical element, which is intended to adapt a position of the means in the path at least partially automatically to conditions of a measurement. The control unit can move the device during a distance measurement. In particular, the precision of the distance measurement can be increased with changing measurement conditions. A measurement condition may e.g. an orientation of a received measurement signal relative to a receiving optical system, an ambient temperature or an intensity of an ambient light. The adaptation of a position of the means to a measurement condition can be done semi-automatically by a user setting the measurement condition, e.g. a distance range, and input the means into a predetermined condition for the measurement condition, e.g. pre-programmed position is moved by the control unit. It is also conceivable that the adaptation to a measurement condition takes place fully automatically, in that, depending on an actual position of the means in the path, the mean is moved from this actual position into a position adapted to the measurement condition.

In this context, a fully automatic position adaptation of the means can be achieved with a particularly simple construction, if the distance measuring device has a receiving unit for receiving the measuring signal, the control unit being provided, depending on a reception. to adjust the position. In this case, the reception information may be, for example, a signal intensity detected by the receiving unit.

drawing

Further advantages emerge from the following description of the drawing. In the drawings, embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Show it:

1 shows a distance measuring device in a perspective view, FIG. 2a shows a deflection means of the distance measuring device on a deformable carrier plate and a piezoelectric element,

2a shows the arrangement of FIG. 2a in a first deformed position, FIG. 2c shows the arrangement of FIG. 2a in a second deformed position, FIG.

3 shows a further deflecting means on a rod-shaped and deformable carrier element and a piezoelectric element, 4 shows an alternative deflection means on a deformable angle support and two piezoelectric elements,

Fig. 5 shows an alternative deflection and leg-shaped support elements and

Fig. 6 shows an internal circuit of the distance measuring device.

Description of the embodiments

FIG. 1 shows a distance measuring device designed as a laser distance measuring device 10, which has a housing 12. On a support 18 within the housing 12 are designed as a laser diode transmitting unit 20 for generating an optical transmission measurement signal and designed as a photodiode receiving unit 22 for receiving a received measurement signal. For measuring a distance of the laser distance measuring device 10 to a remote object, a transmission measurement signal is transmitted by the transmission unit 20 via a transmission optical system 24 during operation of the laser range finding device 10. The transmission measurement signal reflected from a surface of the remote object is received by the reception unit 22 via a reception optical system 26 and a path 28 as a reception measurement signal. In the path 28, a means 30 for processing the received measurement signal is arranged, which is formed in the considered embodiment as a deflection means for deflecting the received measurement signal. The means 30 is arranged in an adjusting unit 32, which is provided with e-lektromechanischen elements shown in the following figures for moving the means 30. The adjusting unit 32 is in the operation of La serentfernungsraessgeräts 10 controlled by a control unit 34. From a phase comparison carried out between the transmission measurement signal and the reception measurement signal, a light transit time can be determined and the sought distance can be determined via the speed of light.

FIGS. 2a, 2b, 2c show the means 30, which is designed as deflection means, and which is carried by a carrier element 36 designed as a carrier plate. The support member 36 is formed of an elastomer and with a reflective

Layer coated, which forms the means 30. To deform the carrier element 36, an electromechanical element 38, designed as a piezoelectric element, of the adjusting unit 32 is provided, which is glued to the carrier element 36. By applying an electrical voltage between two contact points of the electromechanical element 38, which is connected by electrical connections 44, 46 to the control unit 34, a mechanical deformation of the electromechanical element 38 is generated. In this deformation, the carrier element 36 bearing against the electromechanical element 38 is deformed with the reflective layer formed as a means 30. FIG. 2b shows the arrangement shown in FIG. 2a after application of an electrical voltage. In Figure 2c, this arrangement is shown again, after applying a voltage with reverse polarity.

FIG. 3 shows an alternative embodiment of a carrier element 48 for a deflection means. The carrier element 48 is formed by a rod-shaped elastomer which is coated at one end with a reflective layer, which is implemented as means 52 for redirecting the received measurement signal. At an other end of the rod-shaped support member 48 is a piezoelectric element designed as an electromechanical element 56 of the adjusting unit 32 is glued, which is electrically connected via not shown electrical connections to the control unit 34. By applying an electrical voltage, an expansion of the electromechanical element 56 is induced, which in turn generates a lever movement of the carrier element 48 in a direction 66. When an electrical voltage of the opposite polarity is applied, contraction of the electromechanical element 56 and with it a lever movement of the carrier element 48 in a direction opposite to the direction 66 are generated.

A further embodiment of a carrier element 68 for a deflection means is shown in FIG. 4 in a plan view. This is formed by an angular elastomer on which a reflecting plate formed as a means 70 is arranged. This is applied to a support surface 72 of the support member 68 and is glued to two splices 74, 76 to the support member 68. On one of the support surface 72 opposite side of the support member 68 are formed as piezoelectric elements electromechanical elements EI- elements 78, 80 of the adjusting unit 32 glued, each electrically connected to a contact point 82 and 84 and an electrical connection, not shown, to the control unit 34 are. The electromechanical elements 78, 80, which adjoin one another, are also connected via a common ground connection 86 to a ground line of the adjusting unit 32. By applying an electrical voltage At one of the contact points 82, 84, a deformation of the corresponding electromechanical element 78 or 80 is induced. This creates a deformation of the carrier element 68 in a direction 88 or 90, wherein a lifting movement of the means 70 is generated relative to the support surface 72. In one embodiment, it is conceivable that the electromechanical elements 78, 80 rest against each other separately on the carrier element 68.

Figure 5 shows an alternative embodiment of a means 92 for redirecting the received measurement signal. This is formed by a reflective plate, which is supported by three leg-shaped elements. The leg-shaped elements are each formed by an electromechanical element 94 or 96, 98 of the adjusting unit 32, which is designed as a piezoelectric element and which is attached to a support plate 100 on the one hand and to the reflective plate on the other hand by gluing. In addition, the electromechanical elements 94, 96, 98 are each electrically connected at a contact point via an electrical connection see 108 or 110, 112 (Figure 6) to the control unit 34 and connected via their adhesive connection to a ground line of the support plate 100. By applying an electrical voltage to one of the contact points, an expansion or contraction of the corresponding electromechanical element 94 or 96, 98 is induced, wherein a movement of the means 92 is generated.

An internal circuit of the laser range finding device 10 is shown schematically in FIG. Evident are formed as a photodiode receiving unit 22, the control unit 34 and formed as a reflective plate means 92nd for redirecting the received measurement signal. On the means 92 on the one hand and on the support plate 100 on the other hand, the electromechanical elements 94, 96, 98 are attached. These are each electrically connected to the control unit 34 via one of the electrical connections 108, 110, 112. When measuring a distance to a first measurement object, a reception measurement signal is received by the reception unit 22 via the reception optics 26 (FIG. 1) and a path 116. In this configuration, the receive measurement signal deflected by the means 92 falls parallel to an optical axis 118 of FIG

Receiving unit 22 to the receiving unit 22. In a measurement of a distance to a second measurement object, the received measurement signal is received, for example due to a parallax effect, via a path 122 from the receiving unit 22, which forms an angle OC with the optical axis 118 of the receiving unit 22. As a result, only a fraction of a light intensity of the received measuring signal can be detected by the receiving unit 22. To compensate for this reduction in the detected light intensity, the means 92 can be adjusted by the control unit 34 generates deformations of the electromechanical elements 94, 96, 98 by applying electrical voltages via the electrical connections 108, 110, 112. This adjustment can be done in a fully automatic manner. For this purpose, the receiving unit 22 is connected to the control unit 34 via a connection 124. During a measurement, an electrical signal in the form of an electrical voltage V, which is proportional to the light intensity detected by the receiving unit 22, is transmitted via the terminal 124 to the control unit 34. When the light intensity detected by the receiving unit 22 or the voltage V given to the control unit 34 drops below a predetermined threshold, the means 92 is adjusted by the control unit 34 until the detected light intensity or the voltage V reaches the predetermined threshold again.

Claims

23. 08. 05ROBERT BOSCH GMBH; D-70442 Stuttgart claims

1. Distance measuring device, in particular a handheld laser distance measuring device (10), with a path (28, 116, 122) for a measuring signal, means (30, 52, 70, 92) for processing the measuring signal and an adjusting unit (32) for moving the means (30, 52, 70, 92), characterized in that the adjusting unit (32) comprises an electromechanical element (38, 56, 78, 80, 94, 96, 98).

2. Distance measuring device according to claim 1, characterized in that the adjusting unit (32) for adjusting the means (30, 52, 70, 92) is provided.

3. A distance measuring device according to claim 1 or 2, character- ized in that the electromechanical element (38, 56, 78, 80, 94, 96, 98) for deforming and moving the means (30, 52, 70, 92) through the deformation is provided.

4. Distance measuring device according to one of the preceding claims, characterized in that the electromechanical element (38, 56, 78, 80, 94, 96, 98) is a piezoelectric element.

5. Distance measuring device according to one of the preceding claims, characterized by a provided for deformation support member (36, 48, 68) for supporting the agent

(30, 52, 70) provided for deformation by the electromechanical element (38, 56, 78, 80).

6. Distance measuring device according to claim 5, characterized in that the carrier element (48) to a lever movement by the electromechanical element (56) is drivable.

7. Distance measuring device according to claim 5 or 6, characterized in that the means (70) from a support surface

(72) of the carrier element (68) and the carrier element (68) is provided for deformation in at least two directions (88, 90) of the carrier surface (72).

8. Distance measuring device according to one of the preceding claims, characterized in that the means (30) for deformation by the electromechanical element (38) is provided.

9. Distance measuring device according to one of the preceding claims, characterized in that the means (92) of at least one leg-shaped, the electromechanical element (94, 96, 98) having element is supported.

10. Distance measuring device according to one of the preceding claims, characterized by a control unit (34) for controlling the electromechanical element (94, 96, 98), which is intended to a position of the means (92) in the path (122) at least partially automatically to conditions to adapt to a measurement.

11. Distance measuring device according to claim 10, characterized by a receiving unit (22) for receiving the measuring signal, wherein the control unit (34) is adapted to adjust the position depending on a receiving information.