Disclosure of Invention
The invention aims to solve the technical problem of providing a laser radar multichannel data transmission method, a laser radar and application thereof, and aims to solve the problem that the single-channel data transmission mode of the existing laser radar system cannot meet the condition of large data transmission quantity.
In order to solve the technical problem, the invention is realized in such a way that a laser radar multichannel data transmission method comprises the following steps:
step S1, modulating and converting the measurement data into N paths of standard first electric pulse signals, wherein N is an integer more than 2;
step S2, driving the N paths of first electric pulse signals to light emitting components with different light emitting wavelengths respectively to obtain N paths of optical pulse signals with different wavelengths; filtering the N paths of optical pulse signals with different wavelengths to obtain N paths of optical pulse signals which are mutually separated; the filtering method comprises the steps of filtering optical pulse signals by adopting N narrow-band filtering components with different central wavelengths;
step S3, correspondingly converting the N paths of mutually separated optical pulse signals into N paths of standard second electrical pulse signals;
and step S4, modulating, converting and combining the N paths of second electric pulse signals into measurement data.
Further, in step S3, the N separated optical pulse signals are converted into N standard second electrical pulse signals by N photodiodes having different peak responsivity wavelengths.
A lidar comprising a data transmission module, the data transmission module comprising:
the first modulation conversion unit is used for modulating and converting the measurement data into N paths of standard first electric pulse signals, wherein N is an integer more than 2;
the electric pulse signal conversion unit is used for driving the N paths of first electric pulse signals to drive the light-emitting components with different light-emitting wavelengths respectively to obtain N paths of light pulse signals with different wavelengths; filtering the N paths of optical pulse signals with different wavelengths to obtain N paths of optical pulse signals which are mutually separated; the filtering method comprises the steps of filtering optical pulse signals by adopting N narrow-band filtering components with different central wavelengths;
the optical pulse signal conversion unit is used for correspondingly converting the N paths of separated optical pulse signals into N paths of standard second electrical pulse signals;
and the second modulation conversion unit is used for modulating, converting and combining the N paths of second electric pulse signals into measurement data.
Further, the lidar further comprises:
the distance measurement module is used for measuring distance data of a target object;
the wireless power supply module is used for non-contact energy transmission between the transmitting end of the rotating part and the receiving end of the fixing part;
and the motor driving module is used for driving the ranging module to rotate so as to realize the omnidirectional measurement of the radar.
Further, the distance between the target object and the distance measurement module is measured by adopting a TOF distance measurement technology.
Furthermore, the wireless power supply module is an electromagnetic induction type wireless power supply module, and primary and secondary coils of the electromagnetic induction type wireless power supply module are in an up-down stacking structure.
Further, the motor driving module is a hollow brushless direct current motor.
Use of a lidar as described above for servicing robots, drones and AGV carts.
Compared with the prior art, the invention has the beneficial effects that: the invention converts the measured data into N paths of electric pulse signals, then correspondingly converts the N paths of electric pulse signals into N paths of optical pulse signals with different wavelengths through the light-emitting components with different light-emitting wavelengths, and converts the optical pulse signals into the electric pulse signals and restores the measured data after the data signals are transmitted. Theoretically, the data transmission rate can be doubled by adding one channel, so that the data transmission efficiency is greatly improved, the problem that the data cannot be output in real time when the data volume is too large in the prior art is solved, and the method has a certain value for promoting the application of the multi-line TOF laser radar.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides a laser radar multichannel data transmission method, as shown in figure 1, comprising the following steps:
step S1, modulating and converting the measurement data into N paths of standard first electric pulse signals, wherein N is an integer more than 2;
step S2, driving the N paths of first electric pulse signals to light emitting components with different light emitting wavelengths respectively to obtain N paths of optical pulse signals with different wavelengths; filtering the N paths of optical pulse signals with different wavelengths to obtain N paths of optical pulse signals which are mutually separated; the filtering method comprises the steps of filtering optical pulse signals by adopting N narrow-band filtering components with different central wavelengths;
step S3, correspondingly converting the N paths of mutually separated optical pulse signals into N paths of standard second electrical pulse signals;
and step S4, modulating, converting and combining the N paths of second electric pulse signals into measurement data.
The invention converts the measured data into N paths of electric pulse signals, then correspondingly converts the N paths of electric pulse signals into N paths of optical pulse signals with different wavelengths through the light-emitting components with different light-emitting wavelengths, and converts the optical pulse signals into the electric pulse signals and restores the measured data after the data signals are transmitted. Theoretically, the data transmission rate can be doubled by adding one channel, so that the problem that the multi-line TOF laser radar cannot output in real time due to overlarge data volume is solved, and the method has certain value for promoting the application of the multi-line TOF laser radar.
The invention takes 4-channel (N-4) transmission channel as an example to explain the multi-channel data transmission method in detail, which comprises the following steps:
(1) and modulating and converting the measurement data into a 4-channel standard first electric pulse signal. The method specifically comprises the steps of dividing measurement data into 4 paths of signals to be processed, and then converting the signals to be processed into 4 paths of standard electric pulse signals through signal modulation.
(2) And 4 paths of first electric pulse signals are converted into 4 paths of optical pulse signals with different wavelengths. In the step, the light-emitting component can be driven by the electric pulse signal to obtain the optical pulse signal, preferably an LED lamp, and has a large emission angle and a wide coverage range. For example, 4 LED lamps with different emission wavelengths may be driven by using 4 first electrical pulse signals, and assuming that wavelengths corresponding to light emitted by the 4 LED lamps are 700nm (red), 530nm (green), 480nm (blue), and 400nm (violet), the 4 LED lamps respectively emit optical pulse signals with corresponding wavelengths under the respective excitation of the 4 first electrical pulse signals.
Then filtering the 4 optical pulse signals with different wavelengths to obtain 4 mutually separated optical pulse signals. The principle is as shown in fig. 2, 4 narrow-band filters are used to filter the optical pulse signals, and the central wavelengths of the 4 narrow-band filters are 700nm, 530nm, 480nm and 400nm respectively. For example, light emitted by an LED lamp with a light emission wavelength of 700nm can cover the range of 4 narrow band filters, but can only pass through the narrow band filter with a central wavelength of 700 nm; similarly, light emitted by the LED lamps with other wavelengths can only pass through the corresponding narrow-band filters, so that 4 paths of mutually separated optical pulse signals are obtained, and the wavelengths of the 4 paths of optical pulse signals are different.
(3) Correspondingly converting the 4 paths of mutually separated optical pulse signals into 4 paths of standard second electric pulse signals. The light source (LED) at the transmitting end is arranged on the radar ranging rotating part, so that the transmitting light source of the data transmission module rotates while the receiving end (comprising the filtering and photoelectric conversion parts) is fixed when the data transmission module works. 4 photodiodes with corresponding peak responsivity wavelengths are respectively arranged below the 4 narrow-band filters, and the 4 paths of optical pulse signals are converted into 4 paths of standard second electric pulse signals. For example, a light pulse signal emitted from a 700nm LED lamp can pass through a narrow band filter with a center wavelength of 700nm and then be converted into an electrical pulse signal by a photodiode with a peak response rate wavelength of 700 nm.
(4) And modulating, converting and merging the 4 paths of second electric pulse signals into measurement data, and fig. 3 is a detailed working flow diagram of multi-channel data communication of the invention.
The present invention further provides a laser radar, wherein the data transmission module 1 is as shown in fig. 4, and specifically, the data transmission module includes: a first modulation conversion unit 11, configured to modulate and convert the measurement data into N standard first electrical pulse signals, where N is an integer greater than 2; an electrical pulse signal conversion unit 12, configured to convert the N paths of first electrical pulse signals into N paths of optical pulse signals with different wavelengths; filtering the N paths of optical pulse signals with different wavelengths to obtain N paths of separated optical pulse signals, wherein the filtering method is to filter the optical pulse signals by adopting N narrow-band filtering components with different central wavelengths; an optical pulse signal conversion unit 13, configured to correspondingly convert the N paths of separated optical pulse signals into N paths of standard second electrical pulse signals; and the second modulation conversion unit 15 is configured to modulate, convert, and combine the N paths of second electrical pulse signals into measurement data.
Further, the present invention provides a laser radar as shown in fig. 5, further comprising a ranging
module 2 for measuring distance data of a target object; a wireless
power supply module 3 for non-contact energy transmission between the transmitting end of the rotating part and the receiving end of the fixed part; and the
motor driving module 4 is used for driving the ranging module to rotate so as to realize the omnidirectional measurement of the radar. And the distance between the target object and the distance measurement module is measured by adopting a TOF (time of flight) distance measurement technology. The TOF ranging technology is to measure the phase difference of continuous modulation wave optical signals
The principle of the ranging method is shown in fig. 6, in which the round-trip time t is calculated and the distance is calculated by equation (1).
Where c is the speed of light, about 3 x 108m/s, the continuous modulation wave light signal is sent by the sensor light source, and is received by the sensor detector after being reflected by the measured object, the detector calculates the phase change of the continuous modulation wave light signal according to the number of photoelectrons obtained by multiple accumulation, and the distance L between the sensor and the measured object can be expressed as:
where f is the optical signal modulation frequency, w is the angular frequency and w is 2 pi f,
is the phase difference generated in the process of continuously modulating the wave light signal back and forth.
In the invention, the wireless power supply module preferentially uses electromagnetic induction type wireless power supply, is suitable for near distance transmission, is based on the electromagnetic induction principle, is similar to a transformer, and transmits energy by utilizing the inductive coupling of the primary coil and the secondary coil. In order to further reduce the overall volume of the laser radar, the wireless power supply module is improved, and the internal and external structures (nested arrangement) of the primary and secondary side coils in the prior art are improved into an upper and lower structure (stacked arrangement), as shown in fig. 7.
In the invention, the motor driving module is also improved. The center of the rotor is improved on the basis of a conventional brushless direct current motor, and an output shaft in the prior art is made into a hollow shape, so that an optical channel is provided for wireless optical data transmission.
The invention also provides application of the laser radar, and the laser radar is applied to intelligent equipment such as a service robot, an unmanned aerial vehicle and an AGV.
In summary, the invention provides a laser radar multichannel data transmission method, a laser radar and an application thereof. The invention improves the single-channel transmission data of the laser radar in the prior art into multi-channel transmission data, theoretically, the data transmission rate can be doubled by adding one channel, the data transmission efficiency is greatly improved, and the problem that the laser radar cannot output data in real time when the data volume is overlarge in the prior art is solved. In addition, the invention also improves the wireless power supply module and the motor driving module, further reduces the volume of the laser radar and provides an optical channel for wireless optical data transmission.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.