CN109683154B - Laser radar self-calibration timing device and method based on FPGA - Google Patents
Laser radar self-calibration timing device and method based on FPGA Download PDFInfo
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- 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
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Abstract
The embodiment of the invention provides a laser radar self-calibration timing device and a laser radar self-calibration timing method based on an FPGA (field programmable gate array), wherein the device comprises: the system comprises an external signal source, an external delay module and an FPGA minimum system; the FPGA minimum system comprises: the device comprises a self-calibration module, a time identification module, a timing module and an operation module. The embodiment of the invention realizes the real-time calibration function of the timing unit in the FPGA based on the external delay module, can solve the problems that the timing precision of the conventional TDC technology based on the FPGA is greatly influenced by the external environment and cannot be applied to the complex environment, can improve the complex environment adaptability and the timing precision of the laser radar, and has high stability.
Description
Technical Field
The invention relates to the technical field of laser radar timing, in particular to a laser radar self-calibration timing device and method based on an FPGA (field programmable gate array).
Background
The laser radar is a radar system that detects a characteristic amount such as a position and a velocity of a target by emitting a laser beam. In terms of working principle, the laser radar transmits a detection signal to a target, and then compares a received echo signal reflected from the target with the transmission signal, and after appropriate processing, relevant information of the target, such as target distance, azimuth, height, speed, attitude, even shape and other parameters, can be obtained, so as to detect, track and identify the targets such as airplanes, missiles and the like.
In the prior art, a TDC (time-to-digital converter) with picosecond resolution level is mainly realized on an ASIC chip, but the development period of the ASIC chip is long, and the cost is high; the TDC technology based on the FPGA (field programmable gate array) has low implementation cost, short development period and high design flexibility, but due to the particularity of the internal structure of the FPGA, when the external environment changes, the delay time of the delay unit inside the FPGA changes violently. The timing precision of the conventional TDC technology based on the FPGA is about 70ps-100ps, and when the temperature changes, the timing dispersion is increased. Therefore, the timing precision of the conventional TDC technique based on the FPGA is greatly affected by the external environment, and cannot be applied to a complex environment.
In view of this, how to solve the problem that the timing accuracy of the conventional TDC technology based on the FPGA is greatly influenced by the external environment and cannot be applied to the complex environment becomes a technical problem to be solved at present.
Disclosure of Invention
In order to solve the technical problems, the invention provides a laser radar self-calibration timing device and method based on an FPGA (field programmable gate array), which can solve the problem that the timing precision of the conventional TDC technology based on the FPGA is greatly influenced by external environment and cannot be applied to complex environments.
In a first aspect, the present invention provides a laser radar self-calibration timing device based on an FPGA, including: the system comprises an external signal source, an external delay module and an FPGA minimum system;
the external signal source is used for generating an excitation signal and comprises: a starting signal and an echo signal of laser;
the FPGA minimum system comprises: the device comprises a self-calibration module, a time identification module, a timing module and an operation module;
the self-calibration module is used for generating a calibration starting signal and sending the calibration starting signal to the external delay module when detecting an enabling signal from the moment identification module, resetting and enabling the bit-by-bit adder in the self-calibration module, and calibrating the carry chain step length of the bit-by-bit adder in the self-calibration module when receiving a calibration cut-off signal generated by the external delay module;
the time identification module is used for capturing an initial signal and an echo signal of laser and obtaining timing initial time and timing ending time according to edge information of the initial signal and the echo signal;
the timing module is used for acquiring the carry number and the cycle number in the laser flight cycle according to the timing starting time and the timing ending time acquired by the time identification module;
the operation module is used for calculating and obtaining the laser flight time according to the carry number, the cycle number and the calibrated carry chain step length;
the external delay module is used for carrying out delay offset on the calibration starting signal generated by the self-calibration module, generating a calibration cut-off signal and returning the calibration cut-off signal to the self-calibration module.
Optionally, the external delay module is formed by a delay line, and is specifically configured to perform delay processing on the received calibration Start signal Start _0 to obtain a calibration Stop signal Stop _ 0.
Optionally, the timing module is composed of a timing unit, and a basic structure of the timing unit is a carry chain of the bitwise adder, where a unit step of the bitwise adder, that is, a carry chain unit step size, is a minimum unit of the timing module.
Optionally, the self-calibration module is composed of a time discrimination circuit and a carry chain of the bit-by-bit adder,
the time discriminating circuit is configured to, when an enable signal from the time discriminating module is detected, send a calibration Start signal Start _0 to the external delay module, reset and enable the carry chain of the bitwise adder at the same time, receive a calibration Stop signal Stop _0 generated after the external delay module performs delay processing on the Start _0 signal, obtain a timing Stop time according to the Stop _0 signal, output the timing Stop time to the carry chain of the bitwise adder in the self-calibration module, obtain a carry total length of the carry chain of the bitwise adder in the self-calibration module corresponding to the time, and further obtain a carry chain step length of the bitwise adder in the self-calibration module according to the carry total length and a delay time of the external delay module; and reading the current number of carries n0 and the current number of cycles t0 of the bitwise adder in the self-calibration block when a Stop _0 signal from the external delay block is detected.
Optionally, the time identification module is specifically used for
When an initial signal Start of laser from the external signal source is detected, acquiring a timing initial moment according to edge information of the initial signal, and enabling the timing module to Start carry operation; and when an echo signal Stop of laser from the external signal source is detected, obtaining timing cut-off time according to edge information of the echo signal, pausing carry operation of the timing module and reading the current carry number n and the current cycle number t of a bit-by-bit adder in the timing module.
Optionally, the timing module, in particular for
Carrying out carry operation and successive carry according to the timing starting time obtained by the time discrimination module, and when the carry number reaches the preset maximum carry number N reached by each period, the period number is self-added; and pausing carry operation according to the timing deadline acquired by the time discrimination module.
Optionally, the operation module is specifically used for
Calculating to obtain laser flight time T through a first formula according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length;
wherein the first formula is:
T＝(L/n0)×(t×N+n)
l is a preset value of the external delay module.
In a second aspect, the present invention provides a laser radar self-calibration timing method based on an FPGA, and with the apparatus, the method includes:
when detecting an enabling signal from the moment identification module, the self-calibration module generates a calibration starting signal and sends the calibration starting signal to the external delay module, and simultaneously resets and enables a bit-by-bit adder in the self-calibration module;
the external delay module carries out delay offset on the calibration starting signal generated by the self-calibration module, generates a calibration cut-off signal and returns the calibration cut-off signal to the self-calibration module;
the self-calibration module calibrates the carry chain step length of the bit-by-bit adder in the self-calibration module when receiving a calibration cut-off signal generated by the external delay module;
the timing identification module captures an initial signal and an echo signal of laser generated by an external signal source, and obtains a timing initial time and a timing cut-off time according to edge information of the initial signal and the echo signal;
the timing module obtains the number of carry bits and the number of periods in the laser flight period according to the timing starting time and the timing stopping time obtained by the time identification module;
and the operation module calculates the laser flight time according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length.
Optionally, when the self-calibration module receives a calibration cutoff signal generated by the external delay module, the calibrating the carry chain step of the bitwise adder in the self-calibration module includes:
when detecting an enable signal from the time identifying module, a time identifying circuit in the self-calibration module sends a calibration Start signal Start _0 to the external delay module, simultaneously resets and enables the carry chain of the bitwise adder, receives a calibration Stop signal Stop _0 generated after the external delay module performs delay processing on the Start _0 signal, obtains a timing Stop time according to the Stop _0 signal, outputs the timing Stop time to the carry chain of the bitwise adder in the self-calibration module, obtains a carry total length of the carry chain of the bitwise adder in the self-calibration module corresponding to the time, and further obtains a carry chain step length of the bitwise adder in the self-calibration module according to the carry total length and the delay time of the external delay module; and reading the current number of carries n0 and the current number of cycles t0 of the bitwise adder in the self-calibration block when a Stop _0 signal from the external delay block is detected;
correspondingly, the time discrimination module captures an initial signal and an echo signal of laser generated by an external signal source, and obtains a timing initial time and a timing cut-off time according to edge information of the initial signal and the echo signal, and the time discrimination module comprises:
the time identification module obtains timing starting time according to the edge information of the starting signal when detecting the starting signal Start of the laser from the external signal source, enables the timing module to Start carry operation, obtains timing cut-off time according to the edge information of the echo signal when detecting the echo signal Stop of the laser from the external signal source, pauses the carry operation of the timing module and reads the current carry number n and the current cycle number t of a bitwise adder in the timing module;
correspondingly, the timing module obtains the carry number and the cycle number in the laser flight cycle according to the timing starting time and the timing ending time obtained by the time identification module, and the method comprises the following steps:
the timing module starts carry operation according to the timing starting time obtained by the time identification module, carries the operation in a successive manner, and when the carry number reaches the maximum carry number N reached by each preset period, the period number is added; and pausing carry operation according to the timing deadline acquired by the time discrimination module.
Optionally, the calculating module calculates the laser flight time according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length, and includes:
the operation module calculates laser flight time T through a first formula according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length;
wherein the first formula is:
T＝(L/n0)×(t×N+n)
l is a preset value of the external delay module.
According to the technical scheme, the self-calibration timing device and method for the laser radar based on the FPGA, provided by the embodiment of the invention, realize the real-time calibration function of the internal timing unit of the FPGA based on the external delay module, can solve the problems that the conventional TDC technology based on the FPGA is greatly influenced by the external environment and cannot be applied to the complex environment, can improve the complex environment adaptability and the timing precision of the laser radar, and is high in stability.
Drawings
Fig. 1 is a schematic flow chart of a self-calibration timing method of a laser radar based on an FPGA according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an internal structure of the self-calibration module shown in FIG. 1 according to an embodiment of the present invention;
fig. 3 is a schematic flow chart of a laser radar self-calibration timing method based on an FPGA according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 shows a schematic structural diagram of an FPGA-based lidar self-calibration timing apparatus according to an embodiment of the present invention, and as shown in fig. 1, the FPGA-based lidar self-calibration timing apparatus according to the embodiment includes: an external signal source 11, an external delay module 12 and an FPGA minimum system 13;
the external signal source 11 is configured to generate an excitation signal, and includes: a starting signal and an echo signal of laser;
the external delay module 12 is configured to perform delay offset on a calibration start signal of the self-calibration module 14 generated in the FPGA minimum system 13, generate a calibration cutoff signal, and return the calibration cutoff signal to the self-calibration module 14;
the FPGA minimal system 13 includes: a self-calibration module 14, a time identification module 15, a timing module 16 and an operation module 17;
the self-calibration module 14 is configured to generate a calibration start signal and send the calibration start signal to the external delay module 12 when detecting an enable signal from the time discriminator module 15, reset and enable the bit-by-bit adder in the self-calibration module 14, and calibrate a carry chain step length of the bit-by-bit adder in the self-calibration module 14 when receiving a calibration cutoff signal generated by the external delay module 12;
the time discrimination module 15 is configured to capture an initial signal and an echo signal of the laser, and obtain a timing initial time and a timing ending time according to edge information of the initial signal and the echo signal;
the timing module 16 is configured to obtain the number of carry bits and the number of cycles in the laser flight cycle according to the timing start time and the timing end time obtained by the time identification module 15;
and the operation module 17 is configured to calculate and obtain the laser flight time according to the carry number, the cycle number, and the calibrated carry chain step length.
It can be understood that, when receiving the calibration cutoff signal generated by the external delay module 12, the self-calibration module 14 calibrates the carry chain step of the bit-by-bit adder in the self-calibration module 14, and the obtained carry chain step is a unit step of the laser radar timing; the step length of the carry chain obtained after calibration is as follows: l/n0, where L is the preset value of the external delay module, and n0 is the number of carry bits obtained after the start signal passes through the delay module.
In a specific application, the external delay module 12 may be formed by a delay line, and is specifically configured to perform a delay process on the received calibration Start signal Start _0 to obtain a calibration Stop signal Stop _ 0.
In a specific application, the timing module 16 may be composed of a timing unit, and the basic structure of the timing unit is a carry chain of a bitwise adder, where a unit step of the bitwise adder, that is, a carry chain unit step, is a minimum unit of the timing module.
In a specific application, as shown in fig. 2, the self-calibration module 14 is composed of a time discriminator circuit 18 and a carry chain 19 of a bitwise adder,
the time discriminating circuit 18 is configured to send a calibration Start signal Start _0 to the external delay module 12 when detecting an enable signal from the time discriminating module 15, reset and enable the carry chain 19 of the bitwise adder at the same time, receive a calibration Stop signal Stop _0 generated after the external delay module 12 performs delay processing on the Start _0 signal, obtain a timing Stop time according to the Stop _0 signal, output the timing Stop time to the carry chain 19 of the bitwise adder in the self-calibration module 14, obtain a carry total length of the carry chain 19 of the bitwise adder in the self-calibration module 14 corresponding to the time, and further obtain a carry chain step length of the bitwise adder in the self-calibration module 14 according to the carry total length and the delay time of the external delay module 12; and reading the current number of carries n0 and the current number of cycles t0 of the bitwise adder in the self-calibration block 14 when the Stop _0 signal from the external delay block 12 is detected.
In a specific application, the time identification module 15 can be specifically used for
When the Start signal Start of the laser from the external signal source 11 is detected, obtaining a timing Start time according to edge information (i.e., rising edge information or falling edge information) of the Start signal, and enabling the timing module 16 to Start a carry operation; and when detecting the echo signal Stop of the laser from the external signal source 11, obtaining a timing cutoff time according to edge information (i.e., rising edge information or falling edge information) of the echo signal, suspending the carry operation of the timing module 16 and reading the current carry number n and the current cycle number t of the bit-by-bit adder in the timing module 16.
In particular applications, the timing module 16 may be used in particular
Carrying out carry operation and successive carry according to the timing starting time obtained by the time discrimination module 15, wherein when the carry number reaches the preset maximum carry number N reached by each period, the period number is self-added; and suspending carry operation according to the timing deadline obtained by the time discrimination module 15.
In a specific application, the operation module 17 can be specifically used for
Calculating to obtain laser flight time T through a first formula according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length;
wherein the first formula is:
T＝(L/n0)×(t×N+n) (1)
l is a preset value of the external delay module.
It can be understood that the FPGA minimum system 13 of this embodiment can complete high-precision stable timing with picosecond resolution
The FPGA-based laser radar self-calibration timing device of the embodiment realizes the real-time calibration function of the FPGA internal timing unit based on the external delay module, can solve the problems that the conventional TDC technology based on the FPGA is greatly influenced by the external environment and cannot be applied to the complex environment, can improve the complex environment adaptability and the timing precision of the laser radar, and has high stability.
Fig. 3 is a schematic flow chart of a method for self-calibration timing of a laser radar based on an FPGA according to an embodiment of the present invention, where the method in this embodiment uses the apparatus for self-calibration timing of a laser radar based on an FPGA according to the above embodiment of the present invention, and as shown in fig. 3, the method for self-calibration timing of a laser radar based on an FPGA according to this embodiment is described as follows.
101. When detecting an enabling signal from the time discrimination module, the self-calibration module generates a calibration starting signal and sends the calibration starting signal to the external delay module, and simultaneously resets and enables the bit-by-bit adder in the self-calibration module.
102. The external delay module carries out delay offset on the calibration starting signal generated by the self-calibration module, generates a calibration cut-off signal and returns the calibration cut-off signal to the self-calibration module.
103. And when the self-calibration module receives a calibration cut-off signal generated by the external delay module, the self-calibration module calibrates the carry chain step length of the bit-by-bit adder in the self-calibration module.
It can be understood that, when receiving the calibration cutoff signal generated by the external delay module 12, the self-calibration module 14 calibrates the carry chain step of the bit-by-bit adder in the self-calibration module 14, and the obtained carry chain step is a unit step of the laser radar timing.
In a specific application, the step 103 may include:
when detecting an enable signal from the time identifying module, a time identifying circuit in the self-calibration module sends a calibration Start signal Start _0 to the external delay module, simultaneously resets and enables the carry chain of the bitwise adder, receives a calibration Stop signal Stop _0 generated after the external delay module performs delay processing on the Start _0 signal, obtains a timing Stop time according to the Stop _0 signal, outputs the timing Stop time to the carry chain of the bitwise adder in the self-calibration module, obtains a carry total length of the carry chain of the bitwise adder in the self-calibration module corresponding to the time, and further obtains a carry chain step length of the bitwise adder in the self-calibration module according to the carry total length and the delay time of the external delay module; and reading the current number of carries n0 and the current number of cycles t0 of the bitwise adder in the self-calibration block when a Stop _0 signal from the external delay block is detected.
It can be understood that the step size of the carry chain obtained after calibration is: l/(t0 × N + N0), where L is the preset value of the external delay module, and N is the maximum carry number reached by each cycle preset by the timing module.
104. The time discrimination module captures an initial signal and an echo signal of laser generated by an external signal source, and obtains a timing initial time and a timing cut-off time according to edge information of the initial signal and the echo signal.
In a specific application, the step 104 may include:
the time identification module obtains timing starting time according to the edge information of the starting signal when detecting the starting signal Start of the laser from the external signal source, enables the timing module to Start carry operation, obtains timing cut-off time according to the edge information of the echo signal when detecting the echo signal Stop of the laser from the external signal source, pauses the carry operation of the timing module and reads the current carry number n and the current cycle number t of the bitwise adder in the timing module.
105. And the timing module acquires the carry number and the cycle number in the laser flight cycle according to the timing starting time and the timing ending time acquired by the time identification module.
In a specific application, the step 105 may include:
the timing module starts carry operation according to the timing starting time obtained by the time identification module, carries the operation in a successive manner, and when the carry number reaches the maximum carry number N reached by each preset period, the period number is added; and pausing carry operation according to the timing deadline acquired by the time discrimination module.
106. And the operation module calculates the laser flight time according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length.
In a specific application, the step 106 may include:
the operation module calculates laser flight time T through a first formula according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length;
wherein the first formula is:
T＝(L/n0)×(t×N+n) (1)
l is a preset value of the external delay module.
According to the FPGA-based laser radar self-calibration timing method, the FPGA-based laser radar self-calibration timing device is utilized, a real-time calibration function of an internal timing unit of the FPGA is realized based on an external delay module, the problems that the timing precision of a conventional FPGA-based TDC technology is greatly influenced by an external environment and cannot be applied to a complex environment are solved, the complex environment adaptability and the timing precision of the laser radar can be improved, and the stability is high.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element. The terms "upper", "lower", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the description of the present invention, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention is not limited to any single aspect, nor is it limited to any single embodiment, nor is it limited to any combination and/or permutation of these aspects and/or embodiments. Moreover, each aspect and/or embodiment of the present invention may be utilized alone or in combination with one or more other aspects and/or embodiments thereof.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.
Claims (9)
1. The laser radar self-calibration timing device based on the FPGA is characterized by comprising the following components: the system comprises an external signal source, an external delay module and an FPGA minimum system;
the external signal source is used for generating an excitation signal and comprises: a starting signal and an echo signal of laser;
the FPGA minimum system comprises: the device comprises a self-calibration module, a time identification module, a timing module and an operation module;
the self-calibration module is used for generating a calibration starting signal and sending the calibration starting signal to the external delay module when detecting an enabling signal from the moment identification module, resetting and enabling the bit-by-bit adder in the self-calibration module, and calibrating the carry chain step length of the bit-by-bit adder in the self-calibration module when receiving a calibration cut-off signal generated by the external delay module;
the time identification module is used for capturing an initial signal and an echo signal of laser and obtaining timing initial time and timing ending time according to edge information of the initial signal and the echo signal;
the timing module is used for acquiring the carry number and the cycle number in the laser flight cycle according to the timing starting time and the timing ending time acquired by the time identification module;
the operation module is used for calculating and obtaining the laser flight time according to the carry number, the cycle number and the calibrated carry chain step length;
the external delay module is used for carrying out delay offset on the calibration starting signal generated by the self-calibration module, generating a calibration cut-off signal and returning the calibration cut-off signal to the self-calibration module;
the self-calibration module consists of a time discrimination circuit and a carry chain of a bit-by-bit adder; the time discriminating circuit is configured to send a calibration Start signal Start _0 to the external delay module when an enable signal from the time discriminating module is detected, reset and enable a carry chain of a bitwise adder in the self-calibration module at the same time, receive a calibration Stop signal Stop _0 generated after the external delay module performs delay processing on the Start _0 signal, obtain a timing Stop time according to the Stop _0 signal, output the timing Stop time in the self-calibration module to the carry chain of the bitwise adder in the self-calibration module, obtain a carry total length of the carry chain of the bitwise adder in the self-calibration module corresponding to the time, and further obtain a carry chain step length of the bitwise adder in the self-calibration module according to the carry total length and the delay time of the external delay module; and reading the current number of carries n0 and the current number of cycles t0 of the bitwise adder in the self-calibration block when a Stop _0 signal from the external delay block is detected.
2. The apparatus according to claim 1, wherein the external delay module is formed by a delay line, and is specifically configured to delay the received calibration Start signal Start _0 to obtain the calibration Stop signal Stop _ 0.
3. The apparatus of claim 1, wherein the timing module is composed of a timing unit, and the basic structure of the timing unit is a carry chain of a bitwise adder, wherein a unit step of the bitwise adder, i.e. a carry chain unit step, is a minimum unit of the timing module.
4. Device according to claim 1, characterized in that said moment discrimination module is particularly adapted to
When an initial signal Start of laser from the external signal source is detected, acquiring a timing initial moment according to edge information of the initial signal, and enabling the timing module to Start carry operation; and when an echo signal Stop of laser from the external signal source is detected, obtaining timing cut-off time according to edge information of the echo signal, pausing carry operation of the timing module and reading the current carry number n and the current cycle number t of a bit-by-bit adder in the timing module.
5. Device according to claim 4, characterized in that said timing module, in particular for
Carrying out carry operation and successive carry according to the timing starting time obtained by the time discrimination module, and when the carry number reaches the preset maximum carry number N reached by each period, the period number is self-added; and pausing carry operation according to the timing deadline acquired by the time discrimination module.
6. The device according to claim 5, characterized in that said calculation module is particularly adapted to
Calculating to obtain laser flight time T through a first formula according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length;
wherein the first formula is:
T＝(L/n1)×(t×N+n)
l is a preset value of the delay time of the external delay module, n1 is the total carry length of a carry chain of a bitwise adder in the self-calibration module, the step length of the carry chain obtained after calibration is L/n1, and the carry number and the cycle number in the laser flight cycle are the current carry number n and the current cycle number t of the bitwise adder in the timing module.
7. An FPGA-based lidar self-calibration timing method using the apparatus of any one of claims 1-6, comprising:
when detecting an enabling signal from the moment identification module, the self-calibration module generates a calibration starting signal and sends the calibration starting signal to the external delay module, and simultaneously resets and enables a bit-by-bit adder in the self-calibration module;
the external delay module carries out delay offset on the calibration starting signal generated by the self-calibration module, generates a calibration cut-off signal and returns the calibration cut-off signal to the self-calibration module;
when the self-calibration module receives a calibration cut-off signal generated by the external delay module, the self-calibration module calibrates a carry chain step length of a bit-by-bit adder in the self-calibration module, and the calibration cut-off signal comprises:
when detecting an enable signal from the time identification module, a time identification circuit in the self-calibration module sends a calibration Start signal Start _0 to the external delay module, simultaneously resets and enables a carry chain of a bit-by-bit adder in the self-calibration module, receives a calibration Stop signal Stop _0 generated after the external delay module performs delay processing on the Start _0 signal, obtains a timing Stop time according to the Stop _0 signal, outputs the timing Stop time in the self-calibration module to the carry chain of the bit-by-bit adder in the self-calibration module, obtains a carry total length of the carry chain of the bit-by-bit adder in the self-calibration module corresponding to the time, and further obtains a carry chain step length of the bit-by-bit adder in the self-calibration module according to the carry total length and the delay time of the external delay module; and reading the current number of carries n0 and the current number of cycles t0 of the bitwise adder in the self-calibration block when a Stop _0 signal from the external delay block is detected;
the timing identification module captures an initial signal and an echo signal of laser generated by an external signal source, and obtains a timing initial time and a timing cut-off time according to edge information of the initial signal and the echo signal;
the timing module obtains the number of carry bits and the number of periods in the laser flight period according to the timing starting time and the timing stopping time obtained by the time identification module;
and the operation module calculates the laser flight time according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length.
8. The method of claim 7, wherein the time discriminating module captures a start signal and an echo signal of laser light generated by an external signal source, and obtains a timing start time and a timing end time according to edge information of the start signal and the echo signal, and comprises:
the time identification module obtains timing starting time according to the edge information of the starting signal when detecting the starting signal Start of the laser from the external signal source, enables the timing module to Start carry operation, obtains timing cut-off time according to the edge information of the echo signal when detecting the echo signal Stop of the laser from the external signal source, pauses the carry operation of the timing module and reads the current carry number n and the current cycle number t of a bitwise adder in the timing module;
correspondingly, the timing module obtains the carry number and the cycle number in the laser flight cycle according to the timing starting time and the timing ending time obtained by the time identification module, and the method comprises the following steps:
the timing module starts carry operation according to the timing starting time obtained by the time identification module, carries the operation in a successive manner, and when the carry number reaches the maximum carry number N reached by each preset period, the period number is added; and pausing carry operation according to the timing deadline acquired by the time discrimination module.
9. The method of claim 8, wherein the calculating module calculates the laser flight time according to the number of carry bits in the laser flight period, the number of periods, and the step length of the carry chain obtained after calibration, and includes:
the operation module calculates laser flight time T through a first formula according to the carry number and the cycle number in the laser flight cycle and the calibrated carry chain step length;
wherein the first formula is:
T＝(L/n1)×(t×N+n)
l is a preset value of the delay time of the external delay module, n1 is the total carry length of a carry chain of a bitwise adder in the self-calibration module, the step length of the carry chain obtained after calibration is L/n1, and the carry number and the cycle number in the laser flight cycle are the current carry number n and the current cycle number t of the bitwise adder in the timing module.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101441232A (en) * | 2008-12-25 | 2009-05-27 | 中南大学 | Time base frequency real time calibration frequency measuring method and apparatus |
| CN103837741A (en) * | 2014-03-12 | 2014-06-04 | 河南科技大学 | Equal-precision frequency testing system based on FPGA and design method thereof |
| US8957705B2 (en) * | 2012-09-14 | 2015-02-17 | Intel Corporation | Phase frequency detector |
| CN206193241U (en) * | 2016-09-12 | 2017-05-24 | 北京万集科技股份有限公司 | Range unit of three -dimensional laser |
| CN206311760U (en) * | 2016-12-16 | 2017-07-07 | 北京万集科技股份有限公司 | A kind of laser radar system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9109888B2 (en) * | 2012-03-21 | 2015-08-18 | Honda Motor Co., Ltd. | Distance measuring system |
-
2017
- 2017-10-19 CN CN201710979509.9A patent/CN109683154B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101441232A (en) * | 2008-12-25 | 2009-05-27 | 中南大学 | Time base frequency real time calibration frequency measuring method and apparatus |
| US8957705B2 (en) * | 2012-09-14 | 2015-02-17 | Intel Corporation | Phase frequency detector |
| CN103837741A (en) * | 2014-03-12 | 2014-06-04 | 河南科技大学 | Equal-precision frequency testing system based on FPGA and design method thereof |
| CN206193241U (en) * | 2016-09-12 | 2017-05-24 | 北京万集科技股份有限公司 | Range unit of three -dimensional laser |
| CN206311760U (en) * | 2016-12-16 | 2017-07-07 | 北京万集科技股份有限公司 | A kind of laser radar system |
Non-Patent Citations (1)
| Title |
|---|
| 实时温度补偿的TDC时间间隔测量方法设计与实现;马成等;《全球定位系统》;20141031;第39卷(第5期);第51-54页 * |
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