Abnormal sound monitoring device and method for steering gear
Technical Field
The invention belongs to the technical field of automobile steering gears, and particularly relates to a device and a method for monitoring abnormal sound of a steering gear.
Background
The automobile steering device is used as a basic component of an automobile, the quality of the production quality of the automobile steering device directly influences the perception of automobile driving. Due to the inherent characteristics of materials, the gear rack has certain abrasion, and further causes poor problems such as looseness, abnormal sound and the like, so that the abnormal sound detection is needed after the automobile steering gear is produced, and the automobile steering gear can be sold after being qualified.
At present, abnormal sound in the steering gear industry is generated by shaking the steering gear by a person, attaching ears to the steering gear to identify whether the steering gear has abnormal sound, so that the requirements on the quality and experience of detection personnel are high, and the phenomenon of missing judgment is difficult to avoid. And the online detection is difficult, and the later risk is high.
Disclosure of Invention
In order to overcome the technical defects, the invention provides a steering gear abnormal sound monitoring device and a method, which aim to solve the problems related to the background technology.
The invention provides a monitoring device for abnormal sound of a steering gear, which is arranged on an automobile steering system, wherein the steering system comprises: the steering mechanism comprises a pipe column connected with a steering wheel, an intermediate shaft rotatably mounted on the pipe column, a steering gear rotatably connected with the intermediate shaft through a transition sleeve, and steering output shafts mounted at two ends of the steering gear through inner ball joints;
wherein, a vibration sensor is absorbed on the inner ball joint; and a sensor mounting seat is arranged on the transition sleeve or near the transition sleeve, and an acoustic emission sensor is arranged on the sensor mounting seat.
Preferably or optionally, the vibration sensor is an adsorption sensor, the front end of the vibration sensor is adsorbed on an inner ball joint of the steering gear, the rear end of the vibration sensor is connected with the signal acquisition card, then the signal is transmitted to the signal processing unit, and finally the processed signal is input to the monitoring terminal.
Preferably or optionally, the acoustic emission sensor is a high-sensitivity piezoceramic sensor, and the acoustic emission sensor is selected from R15a, and has a frequency range of 50KHz to 400KHz, wherein the resonance frequency is 150 KHz.
Preferably or optionally, the front end of the acoustic emission sensor is in contact with the transition sleeve, the rear end of the acoustic emission sensor is connected with the preamplifier, the signal is transmitted to the signal acquisition card and the signal processing unit, and finally the processed signal is input to the monitoring terminal.
Preferably or optionally, the sensor mounting seat is fixedly mounted on or near the transition sleeve in a bolt connection manner;
the sensor mount includes: the adjusting knob is arranged on the other side of the body part and penetrates through the body part;
the acoustic emission sensor is fixedly installed in the preset space through the adjusting knob.
Preferably or optionally, the adjusting knob is made of an aluminum metal material, and the adjusting knob includes: the manual knob is arranged on the outer side of the body part and positioned at the upper part, the threaded part penetrates through the body part and positioned on the inner side of the body part, the pressing plate is arranged between the manual knob and the outer side of the body part, and the rubber pad is arranged at the tail end of the threaded part.
Preferably or optionally, the adjustment knob is made of an aluminum metal material.
Preferably or optionally, the monitoring terminal comprises:
the time domain characteristic parameter analysis module is used for processing signals monitored by the vibration sensor and the acoustic emission sensor and generating time domain characteristic parameters, wherein the time domain characteristic parameters comprise a mean value, a root mean square value and a peak-to-peak value;
the power spectrum analysis module is used for displaying in a frequency domain;
the empirical mode decomposition module is used for displaying a time domain;
and the Hilbert conversion module is used for defining instantaneous frequency, instantaneous phase and instantaneous amplitude at any moment, finding instantaneous parameters of short signals and complex signals and further obtaining analytic signals of the monitored signals.
The invention also provides a method for monitoring the abnormal sound of the steering gear, which comprises the following steps:
acquiring first information, wherein the first information comprises signals monitored by a vibration sensor and an acoustic emission sensor;
processing the first information through a time domain characteristic analysis module and generating time domain characteristic parameters, wherein the time domain characteristic parameters comprise a mean value, a root mean square value and a peak-to-peak value;
judging whether the time domain characteristic parameters exceed set corresponding threshold values, wherein the set corresponding threshold values are normal values monitored by a vibration sensor and an acoustic emission sensor when the steering gear has no abnormal sound;
if so, judging that the steering gear generates abnormal sound, and determining that the abnormal sound is generated in the inner ball joint monitored by the vibration sensor and/or the abnormal sound is generated in the shell monitored by the acoustic emission sensor.
Preferably or optionally, when it is determined that abnormal noise occurs inside the casing monitored by the acoustic emission sensor and it is determined that abnormal noise does not occur in the inner ball joint, the monitoring method further includes:
determining an abnormal sound generation interval of the steering gear shell by combining time domain display of the empirical mode decomposition module, a set corresponding threshold and frequency domain display of the power spectrum analysis module;
after the interval is determined, decomposing and reconstructing the signal through a wavelet packet;
instantaneous frequency, instantaneous phase and instantaneous amplitude at any moment are defined through Hilbert transformation, instantaneous parameters of short signals and complex signals are found, and therefore analytic signals of the monitored signals are obtained;
and then, according to an envelope frequency spectrum formed by time-frequency display and analytic signal mode operation of the wavelet packet, obtaining frequencies corresponding to different monitoring parts of the steering gear, and further determining abnormal sound parts inside the steering gear shell.
Has the advantages that: the invention relates to a steering gear abnormal sound monitoring device and a method, wherein a vibration sensor is adsorbed on an inner ball joint, and an acoustic emission sensor is arranged on a transition sleeve or near the transition sleeve, so that a mode that personnel need to attach ears to a steering gear to identify whether the steering gear generates abnormal sound is replaced, and whether the steering gear generates the abnormal sound in the running process can be monitored in real time. The method comprises the steps that time domain characteristic parameter analysis, power spectrum analysis, Empirical Mode Decomposition (EMD) and Hilbert transformation are carried out on obtained information at a monitoring terminal, whether abnormal sound occurs in the steering gear is diagnosed, and when the abnormal sound is judged not to be caused by the inner ball joint, monitoring signals of the acoustic emission sensor are further processed, and the part of the casing, which causes the abnormal sound, is determined.
Drawings
Fig. 1 is a schematic structural diagram of a steering gear abnormal sound monitoring device in the invention.
Fig. 2 is a schematic structural view of a sensor mount according to the present invention.
FIG. 3 is a partial enlarged view of the acoustic emission sensor of the present invention.
Fig. 4 is a schematic block diagram of a monitoring terminal according to the present invention.
Fig. 5 is a flowchart of a method for monitoring abnormal noise of a steering gear according to the present invention.
Fig. 6 is a flow chart of the monitoring terminal signal analysis and abnormal sound judgment in the present invention.
Fig. 7 is a flowchart of the present invention for locating the abnormal sound position of the steering gear housing.
The reference signs are: the device comprises a pipe column 1, an intermediate shaft 2, an inner ball joint 3, a steering gear 4, a transition sleeve 5, a steering output shaft 6, a vibration sensor 7, a sensor mounting seat 8, a body part 81, a bolt 82, a nut 83, an adjusting knob 84, a manual knob 841, a threaded part 842, a pressing plate 843, a rubber pad 844, an acoustic emission sensor 9, a preamplifier 10, a signal acquisition card 11, a signal processing unit 12, a monitoring terminal 13, a time domain characteristic parameter analysis module 131, a power spectrum analysis module 132, an empirical mode decomposition module 133 and a Hilbert transform module 144.
Detailed Description
In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.
Referring to fig. 1 to 4, a steering gear abnormal sound monitoring apparatus includes: the device comprises a pipe column 1, an intermediate shaft 2, an inner ball joint 3, a steering gear 4, a transition sleeve 5, a steering output shaft 6, a vibration sensor 7, a sensor mounting seat 8, a body part 81, a bolt 82, a nut 83, an adjusting knob 84, a manual knob 841, a threaded part 842, a pressing plate 843, a rubber pad 844, an acoustic emission sensor 9, a preamplifier 10, a signal acquisition card 11, a signal processing unit 12, a monitoring terminal 13, a time domain characteristic parameter analysis module 131, a power spectrum analysis module 132, an empirical mode decomposition module 133 and a Hilbert transform module 144.
The monitoring device is arranged on an automobile steering system, wherein the steering system comprises: the steering mechanism comprises a pipe column 1 connected with a steering wheel, an intermediate shaft 2 rotatably mounted on the pipe column 1, a steering gear 4 rotatably connected with the intermediate shaft 2 through a transition sleeve 5, and steering output shafts 6 mounted at two ends of the steering gear 4 through inner ball joints 3; it is characterized in that a vibration sensor 7 is absorbed on the inner ball joint 3; a sensor mounting seat 8 is arranged on the transition sleeve 5 or near the transition sleeve 5, and an acoustic emission sensor 9 is arranged on the sensor mounting seat 8.
Wherein, the frequency range of the vibration sensor 7 is 0.5-7000Hz, the measuring range is + -50 gpk, the sensitivity is 100mv/g, the resolution is 0.0001g, and the working temperature is-55-100 ℃. The vibration sensor 7 is an adsorption type sensor, the front end of the vibration sensor is adsorbed on the inner ball joint 3 of the steering gear 4, the rear end of the vibration sensor is connected with the signal acquisition card 11, the acquired signals are conveyed to the signal processing unit 12 through a cable to be processed, the signal processing unit 12 is connected with the signal acquisition card 11 and the monitoring terminal 13, the monitored signals are processed, and then the processed signals are input to the monitoring terminal 13 for fault identification and safety assessment.
The acoustic emission sensor is a high-sensitivity piezoelectric ceramic sensor, the model is R15a, the frequency range is 50KHz to 400KHz, and the resonance frequency is 150 KHz. The acoustic emission sensor is fixed on a transition sleeve 5 near a shell of a steering gear 4 through a mounting seat, the front end of the acoustic emission sensor is in contact with the transition sleeve 5, the rear end of the acoustic emission sensor is connected with a preamplifier 10, amplified signals are transmitted to a signal processing unit 12 through a cable, the signal processing unit 12 is connected with a signal acquisition card 11 and a monitoring terminal 13, the monitored signals are processed, and then the processed signals are input to the monitoring terminal 13 for fault identification and safety evaluation. The preamplifier 10 is installed at the rear end of the acoustic emission sensor, the signal-to-noise ratio of the voltage signal monitored by the acoustic emission sensor is improved in the signal transmission process, the signal is amplified, and the gain of the signal is 40 dB.
In a further embodiment, referring to fig. 2, the sensor mount 8 is fixedly mounted on the transition sleeve 5 or near the transition sleeve 5 by means of a bolt 82 connection. Referring to fig. 3, the sensor mount 8 includes: a latch-type body 81 having one side fitted to an outer contour of the transition sleeve 5 or the rotary output shaft and the other side having a predetermined space with respect to the transition sleeve 5 or the rotary output shaft, a bolt 82 and a nut 83 provided on one side of the body 81 for fixing the body 81, and an adjustment knob 84 provided on the other side of the body 81 and penetrating the body 81; the adjusting rotary column is made of aluminum metal materials, the upper portion of the adjusting rotary column is a manual knob 841, the lower half portion of the adjusting rotary column is a cylinder with external threads, and the cylinder can be connected with a hole with internal threads of the mounting seat, so that the mounting seat is screwed in the mounting seat in a threaded connection mode, the acoustic emission sensor 9 is fixedly mounted in the preset space through the adjusting knob 84, and the acoustic emission sensor is used for ensuring the stability of the contact surface of the sensor and the transition sleeve 5 of the steering gear 4 and facilitating reliable signal receiving, and ensuring that the sensor keeps relatively static in the monitoring process.
In a further embodiment, the adjustment knob 84 is made of aluminum metal, and the adjustment knob 84 comprises: a manual knob 841 disposed at the outer side of the body part 81 and located at the upper part, a screw part 842 penetrating the body part 81 and located at the inner side of the body part 81, a pressing plate 843 disposed between the manual knob 841 and the outer side of the body part 81, and a rubber pad 844 disposed at the end of the screw part 842. The pressing plate 843 is a common metal flat plate with the thickness of 3mm, and has the function of ensuring that the sensor seat cannot be damaged when the adjusting knob 84 is adjusted inwards; the sensor pad is rubber pad 844, can fix at the regulation spiral post end through the mode of screw connection after the screw in is adjusted the spiral post, avoids adjusting the spiral post and acoustic emission sensor direct contact, leads to the damage of sensor.
Referring to fig. 4, the monitoring terminal 13 includes: a time domain feature parameter analysis module 131, a power spectrum analysis module 132, an Empirical Mode Decomposition (EMD) module, and a Hilbert transform module 144. The time domain characteristic parameter analysis module 131 is configured to process signals monitored by the vibration sensor 7 and the acoustic emission sensor and generate time domain characteristic parameters, where the time domain characteristic parameters include a mean value, a root mean square value, and a peak-to-peak value; the power spectrum analysis module 132 is used for frequency domain display; the empirical mode decomposition module 133 is used for time domain display; the Hilbert transform module 144 is configured to define an instantaneous frequency, an instantaneous phase, and an instantaneous amplitude at any time, and find instantaneous parameters of a short signal and a complex signal, so as to obtain an analytic signal of the monitored signal. The method has the functions of diagnosing whether the abnormal sound occurs in the steering gear 4, and further processing the monitoring signal of the acoustic emission sensor when the abnormal sound is judged not to be caused by the inner ball joint 3 so as to determine the part causing the abnormal sound in the shell.
Referring to fig. 5 to 7, the steps and methods for the monitoring terminal 13 to determine whether the abnormal sound and the abnormal sound part occur to the steering gear 4 are as follows:
s1, processing signals monitored by a vibration sensor 7 and an acoustic emission sensor through a time domain characteristic analysis module to generate time domain characteristic parameters, wherein the time domain characteristic parameters comprise a mean value, a root mean square value and a peak-to-peak value; comparing the time domain characteristic parameters generated by the sensors with the set corresponding threshold values (namely the normal values monitored by the vibration sensor 7 and the acoustic emission sensor when the steering gear 4 has no abnormal sound), judging that the steering gear 4 has abnormal sound when the characteristic parameters exceed the set corresponding threshold values, and determining whether the abnormal sound occurs in the inner ball joint 3 monitored by the vibration sensor 7 or the abnormal sound occurs in the shell monitored by the acoustic emission sensor;
and S2, when the abnormal sound caused by the inner ball joint 3 is determined, but the abnormal sound is generated inside the shell monitored by the acoustic emission sensor, determining the abnormal sound generation interval of the shell of the steering gear 4 by combining time domain display of an Empirical Mode Decomposition (EMD) module, the set corresponding threshold value and frequency domain display of the power spectrum analysis module 132. The time domain display of the empirical mode decomposition module is the sound signal characteristics obtained after noise reduction is carried out on signals through a noise reduction program and external sound interference is filtered, the frequency domain display of the power spectrum analysis module is the spectrogram of the sound signals output by processing the monitored sound signals through Fast Fourier Transform (FFT), and the integral spectrogram waveform of the sound signals is obtained through the power spectrum;
s3, after the interval is determined, signals can be decomposed and reconstructed through the wavelet packet, instantaneous frequency, instantaneous phase and instantaneous amplitude at any moment are defined through Hilbert transformation, instantaneous parameters of short signals and complex signals are found, so that analytic signals of the monitored signals are obtained, envelope frequency spectrums formed by time-frequency display and analytic signal mode operation of the wavelet packet are used, frequencies corresponding to different monitoring parts of the steering gear 4 are obtained, and abnormal sound parts inside a shell of the steering gear 4 are determined.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.