CN115257723B

CN115257723B - Cold-chain logistics vehicle automatic driving steering obstacle avoidance method and system

Info

Publication number: CN115257723B
Application number: CN202211169229.9A
Authority: CN
Inventors: 马海兵; 马琼; 马列; 马敏
Original assignee: Jiangsu Tianyi Aviation Industry Co Ltd
Current assignee: Jiangsu Tianyi Aviation Industry Co Ltd
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2023-01-17
Anticipated expiration: 2042-09-26
Also published as: CN115257723A

Abstract

The invention relates to the technical field of automatic driving, steering and avoiding of logistics vehicles, and discloses an automatic driving, steering and avoiding method and system of a cold-chain logistics vehicle, wherein a laser radar is used for conducting external sensing processing on the surrounding environment of the vehicle to obtain environment sensing parameters; carrying out state perception processing on the motion state of the vehicle based on a vehicle-mounted sensor to obtain motion state perception parameters; transmitting the environment perception parameters and the motion state perception parameters to a control center for area division to respectively obtain an obstacle area and an obstacle avoidance area; the obstacle avoidance area is transmitted to a motor for controlling braking through an electric signal; according to the invention, through special processing means of static environment data, dynamic object data and vehicle motion perception data and by combining designed obstacle avoidance area division rules and analytic modes, the system coordinates braking and steering functions to ensure stable steering while improving the operation accuracy of automatic driving data.

Description

Cold-chain logistics vehicle automatic driving steering obstacle avoidance method and system

Technical Field

The invention relates to the technical field of automatic driving, steering and avoiding of logistics vehicles, in particular to an automatic driving, steering and obstacle avoiding method and system for a cold-chain logistics vehicle.

Background

In recent years, with the rapid development and growth of the automobile industry and artificial intelligence, a visual detection system applied to unmanned three-dimensional road condition obstacles is also rapidly developed, and the existing technical scheme is that point cloud data generated by a laser radar and a two-dimensional camera are generally combined to serve as input information for identifying the road obstacles, but the point cloud of the laser radar is sparse, the cost is high, and the efficiency is low; therefore, a simpler and more efficient method is needed for detecting the roadblock, and the obstacle avoidance requirement of the vehicle in high-speed running is met.

At present, although there is an automobile application of an intelligent unmanned technology, the unmanned technology related to the cold-chain logistics vehicle is not mature, because of the characteristics of the sensor, the distance for predicting the obstacle of the cold-chain logistics vehicle is short, namely, the obstacle avoidance distance is short, and for the cold-chain logistics vehicle running on the expressway, because the speed of the vehicle is fast, the distance for stably avoiding the obstacle is long, so the existing obstacle avoidance technology cannot meet the obstacle avoidance requirement of the cold-chain logistics vehicle running at a high speed.

On the other hand, many existing sensors can cause misjudgment to the cold-chain logistics vehicle obstacle avoidance system due to factors such as output power, obstacle positions, weather environments and the nature of the obstacles, so that danger is brought to people inside and outside the vehicle, and irreparable loss is caused.

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments, and some simplifications or omissions may be made in this section as well as in the abstract and title of the application to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

The present invention has been made keeping in mind the above problems occurring in the prior art.

Therefore, the technical problems to be solved by the invention are as follows: how to obtain accurate obstacle avoidance prejudgment under high-speed driving so as to effectively and safely steer and avoid obstacles.

In order to solve the technical problems, the invention provides the following technical scheme: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

carrying out external perception processing on the surrounding environment of the vehicle by using a laser radar to obtain an environment perception parameter;

carrying out state sensing processing on the self motion state of the vehicle based on a vehicle-mounted sensor to obtain a motion state sensing parameter;

transmitting the environment perception parameters and the motion state perception parameters to a control center for area division to respectively obtain an obstacle area and an obstacle avoidance area;

the obstacle avoidance area is transmitted to a motor for controlling braking through electric signals, and the traction rod drives wheels to steer while the motor controls the braking module to decelerate according to a signal instruction.

As a preferable scheme of the automatic driving steering obstacle avoidance method of the cold-chain logistics vehicle, the method comprises the following steps: obtaining the context-aware parameter includes obtaining the context-aware parameter,

collecting external perception environment information around the vehicle by using a laser radar;

classifying the external perception environment information to respectively obtain static environment data and dynamic object data;

segmenting the road surface, the lane line and the object identification outline of the static environment data to obtain pixel classification parameters;

detecting and processing the 2D/3D object frame of the dynamic object data to obtain frame classification parameters;

and performing time sequence association by combining the ID/track of the dynamic object data, and tracking the frame classification parameters to obtain the relative distance, speed and orientation of the dynamic object data.

As a preferred scheme of the automatic driving, steering and obstacle avoiding method of the cold-chain logistics vehicle, the method comprises the following steps: obtaining the motion state perception parameter may include,

acquiring the running speed, the crankshaft rotation angle, the heading angle of a vehicle body, the wheel deflection angle, the central speeds of a front axle and a rear axle, the wheel base, the engine running condition and the medium temperature of the vehicle by using the vehicle-mounted sensor;

carrying out vehicle dynamics and vehicle kinematics calculation on the vehicle, and outputting to obtain the state quantity and the control quantity of the self motion of the vehicle;

the state quantity and the control quantity are the motion state perception parameters.

As a preferred scheme of the automatic driving, steering and obstacle avoiding method of the cold-chain logistics vehicle, the method comprises the following steps: performing the division of the region includes performing the division of the region,

setting a region division rule in the control center based on an unmanned automatic steering safety obstacle avoidance principle;

transmitting the pixel classification parameters of the static environment data, the relative distance, speed and orientation of the dynamic object data, the state quantity and the control quantity to the control center through electric signals;

the control center starts the region division rule and analyzes the transmitted parameters;

and carrying out region division according to the analysis result.

As a preferred scheme of the automatic driving, steering and obstacle avoiding method of the cold-chain logistics vehicle, the method comprises the following steps: setting the region division rule includes setting a region division rule including,

constructing a perception parameter database by using a data acquisition technology;

taking the perception parameter database as a sample set, and taking transmission parameters needing to be divided as a test set;

the perception parameter database and the transmission parameters are subjected to KNN-based thought operation in the same feature space;

calling a path plan of the vehicle-mounted navigation system, and reading an operation program of the global path plan;

utilizing coding software to lead the operation result into the operation program of the global path planning in the form of operation parameters for fusion operation;

the area where the travelable route is located is divided into obstacle avoidance areas, the area where the non-travelable route is located is divided into obstacle areas, and the safe braking distance is set to be 5 meters.

As a preferred scheme of the automatic driving, steering and obstacle avoiding method of the cold-chain logistics vehicle, the method comprises the following steps: the performing of the resolving includes performing the resolving by,

calculating the distance from the point where the transmission parameter needs to be divided to the midpoint of the perception parameter database based on a KNN thought;

selecting k points closest to the middle point in the perception parameter database according to ascending distance sequence, and performing weighted average calculation;

and dividing points where the transmission parameters with larger weight ratio are located into corresponding areas by combining the calculation result of the weighted average.

As a preferred scheme of the automatic driving, steering and obstacle avoiding method of the cold-chain logistics vehicle, the method comprises the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

when the pixel classification parameter of the static environment data and the regional classification component value of the relative distance, speed and orientation of the dynamic object data are more than or equal to the sum vector value of the state quantity and the control quantity, the obstacle area is larger than the obstacle avoidance area, and the vehicle automatically adopts a braking mode;

when the pixel classification parameter of the static environment data and the area division component value of the relative distance, speed and orientation of the dynamic object data are less than the total vector value of the state quantity and the control quantity, the obstacle area is less than the obstacle avoidance area, and the traction rod drives the wheels to steer and avoid the obstacles while the vehicle automatically controls the braking module to decelerate.

The invention also discloses an obstacle avoidance system based on the automatic driving steering obstacle avoidance method of the cold-chain logistics vehicle, which comprises a steering module, wherein the steering module comprises a control rod, a driving motor and a steering piece, the control rod is provided with a corner sensor, and the corner sensor and the driving motor are connected with a controller;

the brake module, the brake module includes footboard, servo assembly, braking component, be provided with stroke sensor on the footboard, stroke sensor and servo assembly are connected the controller, be provided with tachometric sensor on the braking component, tachometric sensor and braking component are connected the controller.

As a preferred scheme of the automatic driving, steering and obstacle avoiding system of the cold-chain logistics vehicle, the system comprises the following steps: the steering mechanism is characterized in that a worm rod is connected to the driving motor, the steering part comprises a steering wheel, a traction rod and a torsion rod, the traction rod is connected with the steering wheel, the torsion rod is in transmission connection with the traction rod, and a worm wheel is arranged on the torsion rod and is in fit connection with the worm rod.

As a preferred scheme of the automatic driving, steering and obstacle avoiding system of the cold-chain logistics vehicle, the system comprises the following steps: the brake assembly comprises a brake master cylinder and a brake drum, a brake shoe is arranged in the brake drum and is connected with the brake drum through a compensating piece, and a compensating wheel cylinder is arranged in the brake drum and is connected with the compensating piece;

the compensation wheel cylinder is connected with the controller.

The invention has the beneficial effects that: according to the method, by means of special processing means of static environment data, dynamic object data and vehicle motion perception data and by combining with designed obstacle avoidance area division rules and analysis modes, the calculation accuracy of automatic driving data is improved, meanwhile, the calculation efficiency is improved, the vehicle can be guaranteed to perform braking action or steering obstacle avoidance action in the shortest time, and the safety of lives and properties of other people and the vehicle is guaranteed; the system provided by the invention coordinates braking and steering functions, ensures steering to be stable, and simultaneously ensures the braking effect.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

fig. 1 is a schematic flow chart of an automatic driving, steering and obstacle avoidance method for a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 2 is a schematic view of a connection structure of an automatic driving steering obstacle avoidance system of a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 3 is a schematic structural diagram of a steering module in an automatic steering and obstacle avoidance system of a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 4 is a schematic structural diagram of a braking module in an automatic driving, steering and obstacle avoidance system of a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 5 is a schematic structural diagram of a brake drum in an automatic driving, steering and obstacle avoiding system of a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 6 is a schematic structural view of an arc-shaped chute in an automatic driving, steering and obstacle avoiding system of a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 7 is a schematic cross-sectional structure view of a round bar penetrating through a brake pad and a brake shoe in an automatic driving, steering and obstacle avoiding system of a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 8 is a schematic structural view of a limiting block in a square groove in an automatic driving steering obstacle avoidance system of a cold-chain logistics vehicle according to an embodiment of the invention;

fig. 9 is a schematic structural view of a brake pad in an automatic steering and obstacle avoidance system of a cold-chain logistics vehicle according to an embodiment of the invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced otherwise than as specifically described herein, and it will be appreciated by those skilled in the art that the present invention may be practiced without departing from the spirit and scope of the present invention and that the present invention is not limited by the specific embodiments disclosed below.

Next, the present invention will be described in detail with reference to the drawings, wherein the cross-sectional views illustrating the structure of the device are not enlarged partially according to the general scale for convenience of illustration when describing the embodiments of the present invention, and the drawings are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

Example 1

Referring to fig. 1, a first embodiment of the present invention provides an automatic driving steering obstacle avoidance method for a cold-chain logistics vehicle, which specifically includes the following steps:

s1: and carrying out external perception processing on the surrounding environment of the vehicle by using the laser radar to obtain an environment perception parameter. It should be noted that obtaining the environmental perception parameter includes:

detecting and processing a 2D/3D object frame of the dynamic object data to obtain frame classification parameters;

and performing time sequence association by combining the ID/track of the dynamic object data, tracking frame classification parameters, and obtaining the relative distance, speed and orientation of the dynamic object data.

S2: and carrying out state perception processing on the motion state of the vehicle based on the vehicle-mounted sensor to obtain motion state perception parameters. It should be noted that, the obtaining of the motion state sensing parameter includes:

acquiring the running speed, the crankshaft rotation angle, the heading angle of a vehicle body, the wheel deflection angle, the central speeds of a front axle and a rear axle, the wheel base, the engine running condition and the medium temperature of the vehicle by using a vehicle-mounted sensor;

the state quantity and the control quantity are motion state perception parameters.

S3: and transmitting the environment perception parameters and the motion state perception parameters to a control center for area division to respectively obtain an obstacle area and an obstacle avoidance area. It should be further noted that the performing the region division includes:

setting a region division rule in a control center based on an unmanned automatic steering safety obstacle avoidance principle;

transmitting the pixel classification parameters of the static environment data, the relative distance, speed, orientation, state quantity and control quantity of the dynamic object data to a control center through electric signals;

the control center starts a region division rule and analyzes the transmitted parameters;

and carrying out region division according to the analysis result.

Further, setting the region division rule includes:

taking a perception parameter database as a sample set, and taking transmission parameters needing to be divided as a test set;

the sensing parameter database and the transmission parameters are subjected to KNN-based thought operation in the same characteristic space;

the operation result is imported into an operation program of the global path planning in the form of operation parameters by using coding software to perform fusion operation;

Specifically, the analyzing includes:

calculating the distance from the point where the transmission parameter to be divided is located to the midpoint of the perception parameter database based on the KNN idea;

selecting k points closest to the middle point in the distance perception parameter database according to ascending order arrangement of the distances, and carrying out weighted average calculation;

and dividing points where the transmission parameters with larger weight ratios are located into corresponding areas by combining the calculation results of the weighted average.

Preferably, the embodiment classifies the areas where the parameters are located according to a weight proportion mode, and obtains the obstacle area and the obstacle avoidance area which are convenient for vehicle reaction, so that the reaction speed of vehicle automatic driving is faster and more accurate, and the phenomenon that an accident occurs due to self-judgment time difference of vehicle automatic driving is avoided.

S4: the obstacle avoidance area is transmitted to a motor for controlling steering through electric signals, and the motor controls the braking module to decelerate according to a signal instruction, so that the traction rod drives the wheels to steer. What should be further described in this step is:

when the pixel classification parameter of the static environment data and the area classification component value of the relative distance, speed and orientation of the dynamic object data are more than or equal to the sum vector value of the state quantity and the control quantity, the obstacle area is larger than the obstacle avoidance area, and the vehicle automatically adopts a braking mode;

Example 2

Referring to 1~9, a second embodiment of the present invention, which is different from the first embodiment, provides an automatic steering obstacle avoidance system for a cold-chain logistics vehicle, specifically including:

the steering module 100 comprises a control rod 101, a driving motor 102 and a steering piece 103, wherein a rotation angle sensor 101a is arranged on the control rod 101, and the rotation angle sensor 101a and the driving motor 102 are connected with a controller 300; the brake module 200 comprises a pedal 201, a servo assembly 202 and a brake component 203, wherein the pedal 201 is provided with a stroke sensor 201a, the stroke sensor 201a and the servo assembly 202 are connected with a controller 300, the brake component 203 is provided with a rotating speed sensor 400, and the rotating speed sensor 400 and the brake component 203 are connected with the controller 300.

The driving motor 102 is connected with a scroll 102a, the steering element 103 comprises a steering wheel 103a, a traction rod 103b and a torsion bar 103c, the traction rod 103b is connected with the steering wheel 103a, the torsion bar 103c is in transmission connection with the traction rod 103b, the torsion bar 103c is provided with a worm gear 103d, and the worm gear 103d is in fit connection with the scroll 102 a.

The brake assembly 203 comprises a brake master cylinder 205 and a brake drum 204, wherein a brake shoe 204a is arranged in the brake drum 204, the brake shoe 204a is connected with the brake drum 204 through a compensating piece 204b, and a compensating wheel cylinder 204c is arranged in the brake drum 204 and is connected with the compensating piece 204 b;

the compensating wheel cylinder 204c is connected to the controller 300.

The servo assembly 202 is connected with a brake master cylinder 205; the brake assembly 203 comprises a brake drum 204, a brake shoe 204a and a fixed block 204d, the fixed block 204d and the brake shoe 204a are arranged in the brake drum 204, one end of the brake shoe 204a is connected with the fixed block 204d through a compensating piece 204b, a brake block 204e is arranged on the brake shoe 204a, a brake wheel cylinder 204f is further arranged in the brake drum 204, and the brake wheel cylinder 204f is communicated with a brake master cylinder 205.

Specifically, the servo assembly 202 is a motor servo brake assembly, and includes a servo motor 202a for connection, it should be noted that the servo assembly 202 senses the stroke of the brake pedal and the braking intention of the driver by using a stroke sensor 201a, and transmits a signal to the controller for driving, the servo motor 202a drives a worm, a turbine, a gear, a rack and other transmission parts and pushes the brake master cylinder 205 to work, thereby implementing electric servo braking, and further, the brake master cylinder 205 is provided with an oil can 205a.

When the driver controls the system, the active control system can realize the power-assisted braking function, and the power-assisted control is smooth; the brake-by-wire function can be realized, and the response speed of the brake-by-wire is high.

When the driver does not control the vehicle, the servo motor 202a can be autonomously and correspondingly controlled to drive the brake master cylinder 205 to work according to the detection condition of the environment, such as an obstacle in a certain distance ahead, and the braking is performed according to the detection signal.

After long-term use, when the brake function is detected to be reduced (the same condition is detected when the pedal 201 moves, and the speed of reduction of the rotating speed of the brake drum 204 is reduced), the control compensator 204b performs compensation adjustment on the brake shoe 204a, and the brake effect is improved.

Specifically, the brake shoes 204a are symmetrically arranged on two sides of the fixed block 204d, the other ends of the brake shoes 204a are in contact with piston rods of the brake wheel cylinders 204f, and the brake shoes 204a are connected through the restraining springs 204 g.

It should be noted that, the compensator 204b is normally balanced and fixed, the brake shoes 204a disposed on both sides of the fixed block 204d can rotate around the compensator 204b, the restraining spring 204g is connected to one end of the brake shoe 204a away from the fixed block 204d, so that the restraining spring 204g is kept in an inward buckled state, while one end of the brake shoe 204a away from the fixed block 204d is always in contact with the piston rod of the brake cylinder 204f, and when the brake cylinder 204f operates, the brake shoe 204a is driven to rotate around the connection with the compensator 204b, so that the brake shoe 204a expands outward, and the brake shoe 204e on the brake shoe 204a contacts and presses the brake drum 204, so that the brake drum 204 is decelerated.

Further, an arc-shaped chute 203a is arranged in the fixed block 204d, and the circle center of the arc-shaped side edge of the arc-shaped chute 203a is the end part of the piston rod of the brake wheel cylinder 204 f; the arc-shaped sliding grooves 203a are symmetrically arranged in the fixing block 204 d.

It should be noted that, when the brake cylinder 204f is in the non-braking initial state, the end of the piston rod of the brake cylinder 204f is located at the center of the arc-shaped side of the arc-shaped sliding slot 203a, that is, when the driving member 204 moves in the arc-shaped sliding slot 203a, the brake shoe 204a will rotate around the end of the piston rod of the brake cylinder 204f, and the brake shoe 204a expands to be closer to the inner side of the brake drum 204, so as to compensate the wear of the brake pad 204e in long-term use.

Further, the compensating member 204b includes a sliding plate 204b-1 and a side block 204b-2, an opening is provided on both sides of the fixed block 204d, and the side block 204b-2 passes through the opening to be coupled with the end shaft of the brake shoe 204 a.

It should be noted that the upper and lower side surfaces of the sliding plate 204b-1 are arc structures attached to the arc chute 203a, the side block 204b-2 is a triangular block structure disposed on the side surface of the sliding plate 204b-1, the top of the side block is provided with a round corner, the two sides of the top are provided with round shafts, the end of the brake shoe 204a is provided with a round hole, the round shafts are embedded in the round holes, and the brake shoe 204a can rotate around the round shafts.

Further, a stabilizing spring 204b-3 is arranged on the side surface of the sliding plate 204b-1 and connected with the end wall of the arc-shaped sliding chute 203 a; the fixed block 204d is provided with a compensation wheel cylinder 204c, and a push rod of the compensation wheel cylinder 204c is arranged between the two sliding plates 204 b-1.

The compensating wheel cylinder 204c is used for controlling the movement of the sliding plate 204b-1, and in an initial state, the stabilizing spring 204b-3 presses the sliding plate 204b-1 to enable the sliding plate 204b-1 to maintain balance only by a push rod of the compensating wheel cylinder 204c, at the moment, the compensating piece 204b is fixed, and the brake shoe 204a can rotate to achieve a braking effect.

When the braking compensation needs to be adjusted, the compensating wheel cylinder 204c acts to compress the stabilizing spring 204b-3 to push the compensating piece 204b to move, and a new balance state is achieved.

Furthermore, according to the brake shoe, an arc-shaped groove 204a-1 is formed in the outer side surface of the brake shoe 204a, the brake pad 204e is embedded in the arc-shaped groove 204a-1, and the end part of the brake pad 204e is connected with the end wall of the arc-shaped groove 204a-1 through the first spring 204 a-2; side grooves 204a-3 are arranged on two sides of the bottom of the arc-shaped groove 204a-1, a limit plate 204e-1 is arranged on the inner side of the brake pad 204e, and the limit plate 204e-1 is embedded in the side grooves 204 a-3.

The brake pad 204e is restrained by the connection structure of the stopper plate 204e-1 and the side groove 204a-3, so that the brake pad 204e can rotate only in the circumferential direction of the brake shoe 204a (circumferential direction of the brake drum 204) and cannot move in the radial direction of the brake drum 204.

Furthermore, a key slot hole 204e-2 is arranged on the brake pad 204e from the side, and a square slot 204e-3 is arranged between the key slot holes 204 e-2; the key slot hole 204e-2 is provided with a round bar 206, the round bar 206 is provided with a limiting block 206a, and the limiting block 206a is embedded in the square slot 204e-3 and is connected with the side wall of the square slot 204e-3 through a second spring 206 b.

It should be noted that the second spring 206b pushes the limiting block 206a, and the key slot 204e-2 is provided to allow the circular rod 206 to move relative to the stopper 204e to a certain extent, so as to prevent the circular rod 206 from being locked.

The inner wall of the brake drum 204 is provided with a bottom groove 207, and the end part of the round rod 206 is embedded in the bottom groove 207 and is in contact with the upper side wall of the bottom groove 207; through holes 204a-4 are formed in two side walls of the arc-shaped groove 204a-1, and a round rod 206 is arranged through the through holes 204 a-4.

Furthermore, the brake block 204e makes the round rod 206 always contact with the upper sidewall of the bottom slot 207 under the pulling force of the first spring 204a-2, and during braking, the brake shoe 204a drives the brake block 204e to rotate around one end of the compensation piece 204b, and the round rod 206 does not contact with the upper sidewall of the bottom slot 207 at this time.

One side of the through hole 204a-4 is provided with a bevel serrated edge 204a-5.

Specifically, in the adjustment compensation process of the present invention, the compensating wheel cylinder 204c drives the compensating piece 204b to move to both sides, and the brake shoe 204a rotates around the end of the push rod of the brake wheel cylinder 204f, and in this process, taking the left structure shown in fig. 5 as an example, the brake shoe 204a moves obliquely upward to the left, and in order to drive the brake pad 204e to move obliquely upward to the left, since the round rod 206 has contacted the upper side wall of the bottom groove 207 and cannot move further upward, the brake pad 204e is restricted from moving, and the brake shoe 204a moves upward relative to the brake pad 204 e.

In the initial state, the round bar 206 is clamped at the teeth at the upper right corner shown in fig. 7 under the pulling force of the first spring 204a-2 and the pushing force of the second spring 206b, when the brake shoe 204a moves upwards relative to the brake pad 204e, the second spring 206b always keeps pushing the round bar 206 leftwards, so that when the compensating wheel cylinder 204c slowly pushes the compensating piece 204b to move to a certain extent, the round bar 206 will move from the teeth at the upper right corner to the lower left corner, clamped on the teeth at the lower side, and at the same time, the first spring 204a-2 is stretched, and the brake pad 204e moves in the arc-shaped groove 204 a-1.

It should be noted that the above-described configuration and operation are provided for the purpose of adjusting the contact portion between the brake pad 204e and the brake drum 204, and when the brake is applied, the contact portion between the brake pad 204e and the brake drum 204 is stable, and this area is a certain area on the brake pad 204e, and the area is worn by long-term contact during the application of the brake.

Further, the braking process is as follows:

the servo assembly 202 controls the action of the brake master cylinder 205 according to the pedal stroke signal acquired by the stroke sensor 201 a;

the brake wheel cylinder 204f pushes the brake shoe 204a to rotate, and the brake pad 204e is pressed and contacted with the brake drum 204;

the rotation speed sensor 400 acquires a rotation speed signal of the brake drum 204 and feeds back the signal to the servo assembly 202;

if the speed of the reduction of the rotational speed of the brake drum 204 does not meet the preset value, the compensation wheel cylinder 204c is controlled to perform compensation adjustment.

It should be noted that, the invention is also provided with a controller for processing the signal received by the sensor, when the driver drives normally, the electric servo brake assembly is in the power-assisted brake mode, when the driver brakes, the electric servo brake assembly applies the required brake force according to the pedal stroke of the driver, and is used for the power-assisted brake of the conventional driving; when the vehicle is in a remote position, the electric servo brake assembly responds to an autonomous braking command sent by the controller and implements active braking according to a target braking pressure request sent by the controller.

During braking, the travel sensor 201a returns to the brake pedal travel of the pedal, the controller judges the braking intention of the driver, and transmits a signal to the servo motor 202a, so that the brake master cylinder 205 is actuated, and then the brake assembly 203 is actuated correspondingly to brake.

It should be noted that, during the braking process, the controller determines the braking condition according to the rotation speed of the brake drum 204 transmitted back by the rotation speed sensor 400, and feeds back the braking condition to the servo assembly 202 for feedback regulation.

Further, during the braking process, the controller 300 further determines the braking effect of the braking component 203, that is, whether the braking component 203 meets the expected braking requirement under the same braking requirement, if the speed of the brake drum 204 in 2s should be reduced to 0 and the speed of the brake drum 204 in 5s is reduced to 0 under the same condition, the compensation wheel cylinder 204c is used for performing the braking compensation adjustment.

Specifically, the compensating wheel cylinder 204c drives the compensating element 204b to move towards both sides, and the brake shoe 204a rotates around the end of the push rod of the brake wheel cylinder 204f, in this process, taking the structure on the left side as shown in fig. 4 as an example, the whole brake shoe 204a moves obliquely upward to the left, and in order to drive the brake pad 204e to move obliquely upward to the left, since the circular rod 206 contacts the upper side wall of the bottom groove 207 and cannot move further upward, the brake pad 204e is restricted from moving, and the brake shoe 204a moves upward relative to the brake pad 204 e.

According to the adjustment degree, the brake block 204e is continuously moved, and the contact position of the brake block 204e and the brake drum 204 is adjusted, so that the braking capacity is further compensated.

It is important to note that the construction and arrangement of the present application as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in this application. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of this invention. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present inventions. Therefore, the present invention is not limited to a particular embodiment, but extends to various modifications that nevertheless fall within the scope of the appended claims.

Moreover, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not be described (i.e., those unrelated to the presently contemplated best mode of carrying out the invention, or those unrelated to enabling the invention).

It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims

1. An automatic driving steering obstacle avoidance system based on an automatic driving steering obstacle avoidance method of a cold-chain logistics vehicle is characterized in that: the automatic driving, steering and obstacle avoiding method for the cold-chain logistics vehicle comprises the following steps,

carrying out state perception processing on the motion state of the vehicle based on a vehicle-mounted sensor to obtain motion state perception parameters;

the obstacle avoidance area is transmitted to a motor for controlling braking through an electric signal, and the traction rod drives wheels to steer while the motor controls the braking module to decelerate according to a signal instruction;

obtaining the context-aware parameter includes obtaining the context-aware parameter,

performing time sequence association by combining the ID/track of the dynamic object data, and tracking the frame classification parameters to obtain the relative distance, speed and orientation of the dynamic object data;

obtaining the motion state perception parameter may include,

the state quantity and the control quantity are the motion state perception parameters;

performing the division of the region includes performing the division of the region,

carrying out region division according to the analysis result;

setting the region division rule includes setting a region division rule including,

the operation result is imported into the operation program of the global path planning in the form of operation parameters by using coding software to perform fusion operation;

dividing the area where the drivable route is located into obstacle avoidance areas, dividing the area where the undrivable route is located into obstacle areas, and setting the safe braking distance to be 5 meters;

the performing of the resolving includes performing the resolving by,

dividing points where the transmission parameters with larger weight ratio are located into corresponding areas by combining the results of weighted average calculation;

when the pixel classification parameter of the static environment data plus the regional classification component value of the relative distance, speed and orientation of the dynamic object data is larger than or equal to the total vector value of the state quantity plus the control quantity, the obstacle area is larger than the obstacle avoidance area, and the vehicle automatically adopts a braking mode;

when the pixel classification parameter of the static environment data and the area division component value of the relative distance, speed and orientation of the dynamic object data are less than the sum vector value of the state quantity and the control quantity, the obstacle area is less than the obstacle avoidance area, and the traction rod drives wheels to steer and avoid obstacles while the vehicle automatically controls the braking module to decelerate;

the automatic driving steering obstacle avoidance system comprises a steering wheel,

the steering control system comprises a steering module (100), wherein the steering module (100) comprises a control rod (101), a driving motor (102) and a steering piece (103), a rotation angle sensor (101 a) is arranged on the control rod (101), and the rotation angle sensor (101 a) and the driving motor (102) are connected with a controller (300);

the brake module (200) comprises a pedal (201), a servo assembly (202) and a brake component (203), wherein a stroke sensor (201 a) is arranged on the pedal (201), the stroke sensor (201 a) and the servo assembly (202) are connected with the controller (300), a rotating speed sensor (400) is arranged on the brake component (203), and the rotating speed sensor (400) and the brake component (203) are connected with the controller (300); the servo assembly (202) includes a servo motor (202 a),

a worm (102 a) is connected to the driving motor (102), the steering part (103) comprises a steering wheel (103 a), a traction rod (103 b) and a torsion rod (103 c), the traction rod (103 b) is connected with the steering wheel (103 a), the torsion rod (103 c) is in transmission connection with the traction rod (103 b), a worm wheel (103 d) is arranged on the torsion rod (103 c), and the worm wheel (103 d) is in fit connection with the worm (102 a);

the brake assembly (203) comprises a brake master cylinder (205) and a brake drum (204), a brake shoe (204 a) is arranged in the brake drum (204), the brake shoe (204 a) is connected with the brake drum (204) through a compensating piece (204 b), and a compensating wheel cylinder (204 c) is arranged in the brake drum (204) and is connected with the compensating piece (204 b);

the compensation wheel cylinder (204 c) is connected with the controller (300);

the servo assembly (202) is connected with a brake master cylinder (205); the brake assembly (203) comprises a brake drum (204), a brake shoe (204 a) and a fixed block (204 d), the fixed block (204 d) and the brake shoe (204 a) are arranged in the brake drum (204), one end of the brake shoe (204 a) is connected with the fixed block (204 d) through a compensating piece (204 b), a brake pad (204 e) is arranged on the brake shoe (204 a), a brake wheel cylinder (204 f) is further arranged in the brake drum (204), and the brake wheel cylinder (204 f) is communicated with a brake master cylinder (205);

when the reduction of the braking function is detected, the controller controls the compensating piece (204 b) to perform compensation adjustment on the brake shoe (204 a);

the brake shoes (204 a) are symmetrically arranged on two sides of the fixed block (204 d), the other ends of the brake shoes (204 a) are in contact with piston rods of the brake wheel cylinders (204 f), and the brake shoes (204 a) are connected through a restraining spring (204 g);

an arc-shaped sliding chute (203 a) is arranged in the fixed block (204 d), and the circle center of the arc-shaped side edge of the arc-shaped sliding chute (203 a) is the end part of a piston rod of the brake wheel cylinder (204 f); the arc-shaped sliding grooves (203 a) are symmetrically arranged in the fixed block (204 d);

the compensating part (204 b) comprises a sliding plate (204 b-1) and side blocks (204 b-2), openings are formed in two sides of the fixed block (204 d), and the side blocks (204 b-2) penetrate through the openings and are connected with end shafts of the brake shoes (204 a);

a stabilizing spring (204 b-3) is arranged on the side surface of the sliding plate (204 b-1) and connected with the end wall of the arc-shaped sliding chute (203 a); a compensation wheel cylinder (204 c) is arranged on the fixed block (204 d), and a push rod of the compensation wheel cylinder (204 c) is arranged between the two sliding plates (204 b-1);

an arc-shaped groove (204 a-1) is formed in the outer side surface of the brake shoe (204 a), a brake pad (204 e) is embedded in the arc-shaped groove (204 a-1), and the end part of the brake pad (204 e) is connected with the end wall of the arc-shaped groove (204 a-1) through a first spring (204 a-2); side grooves (204 a-3) are arranged on two sides of the bottom of the arc-shaped groove (204 a-1), a limiting plate (204 e-1) is arranged on the inner side of the brake pad (204 e), and the limiting plate (204 e-1) is embedded in the side grooves (204 a-3);

the brake pad (204 e) is provided with key slot holes (204 e-2) from the side surface, and square slots (204 e-3) are arranged between the key slot holes (204 e-2); a round rod (206) is arranged in the key slot hole (204 e-2), a limiting block (206 a) is arranged on the round rod (206), and the limiting block (206 a) is embedded in the square slot (204 e-3) and is connected with the side wall of the square slot (204 e-3) through a second spring (206 b);

a bottom groove (207) is formed in the inner wall of the brake drum (204), and the end of the round rod (206) is embedded in the bottom groove (207) and is in contact with the upper side wall of the bottom groove (207); through holes (204 a-4) are formed in two side walls of the arc-shaped groove (204 a-1), and the round rod (206) penetrates through the through holes (204 a-4);

one side of the through hole (204 a-4) is provided with an inclined sawtooth edge (204 a-5).