Heavy-duty commercial vehicle main-auxiliary combined braking method and system combined with road surface state

Abstract

The invention relates to a heavy-duty commercial vehicle main-auxiliary combined braking method and system combined with a road surface state. The method comprises the steps that vehicle running state information and pedal travel information are obtained in real time; identifying a driver braking intention according to the vehicle running state information and the pedal travel information; acquiring working state information of the windscreen wiper in real time; identifying a road surface state according to the working state information of the windscreen wiper; vehicle running state information and ABS working state information are obtained in real time; auxiliary braking is intervened on the basis of main braking according to the braking intention of a driver and the road surface state in combination with the vehicle running state and the ABS working state, and the intervention proportion of the auxiliary braking is intelligently distributed; according to the invention, the working condition adaptability is improved, the braking safety is improved, and the use and maintenance cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of commercial vehicle technology, and in particular to a method and system for combined main and auxiliary braking of heavy commercial vehicles based on road conditions. Background Technology

[0002] The main braking system is the primary braking method for existing heavy commercial vehicles. The friction pads are used frequently, have a short lifespan, and have high operating and maintenance costs. The auxiliary braking system is controlled to be turned on and off by a separate switch. The main-auxiliary combined braking control system can reasonably increase the proportion of auxiliary braking based on the vehicle configuration and operating conditions, reduce friction pad wear, extend brake life, and reduce operating and maintenance costs. However, the current main-auxiliary combined braking control system is not suitable for low-traction road surfaces such as rain, snow, and slippery surfaces, which affects braking stability. Summary of the Invention

[0003] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a method and system for combined main and auxiliary braking of heavy commercial vehicles that takes into account road conditions.

[0004] To achieve the above objectives, the present invention provides a method for combined primary and auxiliary braking of heavy commercial vehicles based on road conditions, the method comprising: Real-time acquisition of vehicle operating status information and pedal travel information; Identify the driver's braking intention based on vehicle operating status information and pedal travel information; Get real-time information on the working status of the windshield wipers; Identify road conditions based on wiper operating status information; Real-time acquisition of vehicle operating status information and ABS working status information; Based on the driver's braking intention and road conditions, combined with the vehicle's operating status and ABS working status, auxiliary braking is initiated on top of the main braking, and the intervention ratio of auxiliary braking is intelligently allocated.

[0005] As a further explanation of the invention, the real-time acquisition of vehicle operating status information and pedal travel information includes: The vehicle operating status information includes vehicle speed, engine speed, and gear; the pedal travel information includes accelerator pedal opening and brake pedal opening.

[0006] As a further explanation of the invention, the step of identifying the driver's braking intention based on vehicle operating status information and pedal travel information includes: When the vehicle speed is less than the set threshold V1, the accelerator pedal opening is less than or equal to the set threshold P, and the brake pedal opening is greater than or equal to the set threshold b1, the driver's braking intention is identified as low braking. When the set threshold V1 ≤ vehicle speed < set threshold V2, accelerator pedal opening ≤ set threshold P, and brake pedal opening ≥ set threshold b1, the driver's braking intention is identified as light braking; When the set vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the set threshold b1 is less than or equal to the brake pedal opening and less than the set threshold b2, the driver's braking intention is identified as light braking. When the vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the set threshold b2 is less than or equal to the brake pedal opening and less than the set threshold b3, the driver's braking intention is identified as medium braking. When the vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the brake pedal opening is greater than or equal to the set threshold b3, the driver's braking intention is identified as heavy braking.

[0007] As a further explanation of the invention, the step of identifying road surface conditions based on wiper operating status information includes: The wiper operating status information includes on / off status, operating frequency, and speed.

[0008] As a further explanation of the invention, the step of identifying road surface conditions based on wiper operating status information includes: When the wipers are turned on and the wiper motor is working at high speed, the road surface is identified as having low adhesion. When the wipers are on and the wiper motor is working at low speed, or when the wipers are off, the road surface is considered to have high adhesion.

[0009] As a further explanation of the invention, the method of intervening in auxiliary braking on the basis of main braking, based on the driver's braking intention and road conditions, combined with the vehicle's operating state and ABS working state, and intelligently allocating the intervention ratio of auxiliary braking, includes: When the driver's braking intention is identified as low braking, neither the retarder brake nor the engine brake will intervene. When the driver's braking intention is identified as light braking, high-friction road surface, engine speed ≥ set threshold n, and gear not in neutral, only the retarder braking is engaged, and the retarder braking ratio is distributed according to the brake pedal opening. When the driver's braking intention is identified as medium braking, high-friction road surface, engine speed ≥ set threshold n, and gear not neutral, retarder braking and engine braking intervene simultaneously. The retarder braking ratio is allocated according to the brake pedal opening, and the engine braking ratio is allocated according to the brake pedal opening. When the driver's braking intention is identified as heavy braking, high-friction road surface, engine speed ≥ set threshold n, and gear not in neutral, retarder braking and engine braking are engaged simultaneously, with each engagement ratio of 100%. When the driver's braking intention is identified as light, medium, or heavy braking on a low-traction surface, neither the retarder brake nor the engine brake will engage.

[0010] As a further illustration of the invention, the method also includes: If ABS is activated during braking, the retarder braking and engine braking will disengage or remain disengaged throughout the braking process until the braking process ends.

[0011] A combined primary and auxiliary braking system for heavy-duty commercial vehicles, incorporating road conditions, includes the combined primary and auxiliary braking method for heavy-duty commercial vehicles as described in any of the preceding claims, wherein the system comprises: The driver braking intention recognition module is used to identify the driver's braking intention based on the collected vehicle operating status information and pedal travel information. The road surface condition recognition module is used to identify the road surface condition based on the collected wiper operating status information; The brake force distribution module is used to intelligently distribute the intervention ratio of auxiliary braking based on the main braking, according to the collected vehicle operating status information and ABS working status information, combined with the driver's braking intention and road conditions.

[0012] Compared with the prior art, the advantages of the present invention are as follows: 1) Improved adaptability to operating conditions: The wiper's working status can indirectly indicate the road surface's slipperiness, enabling it to adapt to various road conditions, improve its adaptability to operating conditions, and enhance the driver's braking experience; 2) Improved braking safety: The coordinated control of main and auxiliary brakes increases the braking torque required for vehicle deceleration, improving braking performance and indirectly reducing the braking power of the main brake, keeping the brake pads as cold as possible and ensuring the braking performance of the main brake. Furthermore, the system can dynamically adjust the intervention ratio of retarder braking and engine braking based on road conditions and ABS operating information, improving safety on low-traction surfaces. 3) Reduced usage and maintenance costs: The reduced use of the service brakes slows down the wear of the main brake pads, lowering overall operating costs. Furthermore, utilizing the existing wiper system for road surface recognition eliminates the additional costs associated with cameras, radar, or other road surface recognition sensors, thus reducing hardware costs. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the system principle of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments. Example

[0016] like Figure 1 As shown, a combined main and auxiliary braking method for heavy commercial vehicles, taking into account road conditions, includes: Real-time acquisition of vehicle operating status information and pedal travel information; Identify the driver's braking intention based on vehicle operating status information and pedal travel information; Get real-time information on the working status of the windshield wipers; Identify road conditions based on wiper operating status information; Real-time acquisition of vehicle operating status information and ABS working status information; Based on the driver's braking intention and road conditions, combined with the vehicle's operating status and ABS activation status, auxiliary braking is initiated on top of the main braking, and the intervention ratio of auxiliary braking is intelligently allocated. While the main braking is engaged, retarder braking and engine braking are intelligently activated to increase the braking torque required for vehicle deceleration, enabling the vehicle to continuously decelerate or stabilize its speed, thus ensuring vehicle driving safety.

[0017] Real-time acquisition of vehicle operating status information and pedal travel information; including: Vehicle operating status information includes vehicle speed, engine speed, and gear; pedal travel information includes accelerator pedal opening and brake pedal opening.

[0018] Identify the driver's braking intention based on vehicle operating status information and pedal travel information; including: When the vehicle speed is less than the set threshold V1, the accelerator pedal opening is less than or equal to the set threshold P, and the brake pedal opening is greater than or equal to the set threshold b1, the driver's braking intention is identified as low braking. When the set threshold V1 ≤ vehicle speed < set threshold V2, accelerator pedal opening ≤ set threshold P, and brake pedal opening ≥ set threshold b1, the driver's braking intention is identified as light braking; When the set vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the set threshold b1 is less than or equal to the brake pedal opening and less than the set threshold b2, the driver's braking intention is identified as light braking. When the vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the set threshold b2 is less than or equal to the brake pedal opening and less than the set threshold b3, the driver's braking intention is identified as medium braking. When the vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the brake pedal opening is greater than or equal to the set threshold b3, the driver's braking intention is identified as heavy braking.

[0019] As mentioned above, the set threshold V2 > the set threshold V1, and the set threshold b3 > the set threshold b2 > the set threshold b1.

[0020] Identify road conditions based on wiper operating status information; including: The wiper operating status information includes whether it is on / off, operating frequency, and speed. This wiper operating status information can be monitored in real time via the vehicle's CAN bus.

[0021] Identify road conditions based on wiper operating status information; including: When the wipers are turned on and the wiper motor is working at high speed, the road surface is identified as having low adhesion. When the wipers are on and the wiper motor is working at low speed, or when the wipers are off, the road surface is considered to have high adhesion.

[0022] Based on the driver's braking intention and road conditions, combined with the vehicle's operating status and ABS operating status, auxiliary braking is initiated on top of the main braking, and the intervention ratio of auxiliary braking is intelligently allocated; including: When the driver's braking intention is identified as low braking, neither the retarder brake nor the engine brake will intervene. When the driver's braking intention is identified as light braking, high-friction road surface, engine speed ≥ set threshold n, and gear not in neutral, only the retarder braking is engaged, and the retarder braking ratio is distributed according to the brake pedal opening; see Table 1. When the driver's braking intention is identified as medium braking, high-friction road surface, engine speed ≥ set threshold n, and gear not in neutral, retarder braking and engine braking are engaged simultaneously. The retarder braking ratio is allocated according to the brake pedal opening, as shown in Table 1; the engine braking ratio is allocated according to the brake pedal opening, as shown in Table 2. When the driver's braking intention is identified as heavy braking, high-friction road surface, engine speed ≥ set threshold n, and gear not in neutral, retarder braking and engine braking are engaged simultaneously, with each engagement ratio of 100%. When the driver's braking intention is identified as light, medium, or heavy braking on a low-traction surface, neither the retarder brake nor the engine brake will engage.

[0023] Table 1 Retarder Braking Ratio Table 2 Engine Braking Ratio The data in Tables 1 and 2 above are all standardized quantities, and have been reasonably formulated to take into account the different braking experiences of different drivers.

[0024] The method also includes: To address the limitations of windshield wipers, which rely on rain and snow conditions and cannot recognize complex operating conditions (such as icing and snow accumulation), a safety logic is developed based on the ABS operating status. When ABS is activated during braking, the retarder braking and engine braking should be immediately disengaged or remain disengaged until the braking process ends, thereby improving the safety of use on low-adhesion roads.

[0025] Example 2 A combined primary and auxiliary braking system for heavy-duty commercial vehicles, incorporating road conditions, includes the combined primary and auxiliary braking method for heavy-duty commercial vehicles as described in any of the above-mentioned claims. The system comprises: The driver braking intention recognition module is used to identify the driver's braking intention based on the collected vehicle operating status information and pedal travel information. The road surface condition recognition module is used to identify the road surface condition based on the collected wiper operating status information; The brake force distribution module is used to intelligently distribute the intervention ratio of auxiliary braking based on the main braking, according to the collected vehicle operating status information and ABS working status information, combined with the driver's braking intention and road conditions.

[0026] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for combined main and auxiliary braking of heavy commercial vehicles based on road conditions, characterized in that, The method includes: Real-time acquisition of vehicle operating status information and pedal travel information; Identify the driver's braking intention based on vehicle operating status information and pedal travel information; Get real-time information on the working status of the windshield wipers; Identify road conditions based on wiper operating status information; Real-time acquisition of vehicle operating status information and ABS working status information; Based on the driver's braking intention and road conditions, combined with the vehicle's operating status and ABS working status, auxiliary braking is initiated on top of the main braking, and the intervention ratio of auxiliary braking is intelligently allocated.

2. The combined main and auxiliary braking method for heavy commercial vehicles based on road conditions as described in claim 1, characterized in that, The real-time acquisition of vehicle operating status information and pedal travel information includes: The vehicle operating status information includes vehicle speed, engine speed, and gear; the pedal travel information includes accelerator pedal opening and brake pedal opening.

3. The combined main and auxiliary braking method for heavy commercial vehicles based on road conditions as described in claim 2, characterized in that, The step of identifying the driver's braking intention based on vehicle operating status information and pedal travel information includes: When the vehicle speed is less than the set threshold V1, the accelerator pedal opening is less than or equal to the set threshold P, and the brake pedal opening is greater than or equal to the set threshold b1, the driver's braking intention is identified as low braking. When the set threshold V1 ≤ vehicle speed < set threshold V2, accelerator pedal opening ≤ set threshold P, and brake pedal opening ≥ set threshold b1, the driver's braking intention is identified as light braking; When the set vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the set threshold b1 is less than or equal to the brake pedal opening and less than the set threshold b2, the driver's braking intention is identified as light braking. When the vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the set threshold b2 is less than or equal to the brake pedal opening and less than the set threshold b3, the driver's braking intention is identified as medium braking. When the vehicle speed is greater than or equal to the set threshold V2, the accelerator pedal opening is less than or equal to the set threshold P, and the brake pedal opening is greater than or equal to the set threshold b3, the driver's braking intention is identified as heavy braking.

4. The combined main and auxiliary braking method for heavy commercial vehicles based on road conditions as described in claim 3, characterized in that, The step of identifying road surface conditions based on wiper operating status information includes: The wiper operating status information includes on / off status, operating frequency, and speed.

5. The combined main and auxiliary braking method for heavy commercial vehicles based on road conditions as described in claim 4, characterized in that, The step of identifying road surface conditions based on wiper operating status information includes: When the wipers are turned on and the wiper motor is working at high speed, the road surface is identified as having low adhesion. When the wipers are on and the wiper motor is working at low speed, or when the wipers are off, the road surface is considered to have high adhesion.

6. The combined main and auxiliary braking method for heavy commercial vehicles based on road conditions as described in claim 5, characterized in that, The method involves, based on the driver's braking intention and road conditions, combined with the vehicle's operating status and ABS working status, intervening in auxiliary braking on top of the main braking, and intelligently allocating the intervention ratio of the auxiliary braking; including: When the driver's braking intention is identified as low braking, neither the retarder brake nor the engine brake will intervene. When the driver's braking intention is identified as light braking, high-friction road surface, engine speed ≥ set threshold n, and gear not in neutral, only the retarder braking is engaged, and the retarder braking ratio is distributed according to the brake pedal opening. When the driver's braking intention is identified as medium braking, high-friction road surface, engine speed ≥ set threshold n, and gear not neutral, retarder braking and engine braking intervene simultaneously. The retarder braking ratio is allocated according to the brake pedal opening, and the engine braking ratio is allocated according to the brake pedal opening. When the driver's braking intention is identified as heavy braking, high-friction road surface, engine speed ≥ set threshold n, and gear not in neutral, retarder braking and engine braking are engaged simultaneously, with each engagement ratio of 100%. When the driver's braking intention is identified as light, medium, or heavy braking on a low-traction surface, neither the retarder brake nor the engine brake will engage.

7. The combined main and auxiliary braking method for heavy commercial vehicles based on road conditions as described in claim 5, characterized in that, The method further includes: If ABS is activated during braking, the retarder braking and engine braking will disengage or remain disengaged throughout the braking process until the braking process ends.

8. A combined main and auxiliary braking system for heavy-duty commercial vehicles based on road conditions, comprising the combined main and auxiliary braking method for heavy-duty commercial vehicles as described in any one of claims 1-7, characterized in that, The system includes: The driver braking intention recognition module is used to identify the driver's braking intention based on the collected vehicle operating status information and pedal travel information. The road surface condition recognition module is used to identify the road surface condition based on the collected wiper operating status information; The brake force distribution module is used to intelligently distribute the intervention ratio of auxiliary braking based on the main braking, according to the collected vehicle operating status information and ABS working status information, combined with the driver's braking intention and road conditions.

Images