Predictive vehicle cruise control system, method and vehicle including system

Abstract

The invention relates to predictive vehicle cruise control systems, methods, and vehicles incorporating the same. A predictive cruise control system for a vehicle includes: a front topographic information acquisition device for acquiring topographic information within a predetermined distance range on an expected driving road in front of the vehicle while the vehicle is running, the topographic information including at least coordinates and gradient of the expected driving road in front; the task planning device is used for planning operation control of the vehicle on the expected driving road ahead; the overspeed recognition device is used for judging whether the expected speed of the vehicle on the expected driving road in front exceeds a preset protection range or not. When there is a downhill section in the acquired topographic information such that the expected vehicle speed exceeds the predetermined protection range, the task planning device re-plans the operation control of the vehicle so as to (i) temporarily extend the predetermined protection range, or (ii) extend the interval between adjacent braking events.

Description

Predictive vehicle cruise control system, method, and vehicle including the same Technical Field

[0001] The present invention relates to a vehicle cruise control system and a vehicle comprising the same, wherein the cruise control system has an improved brake control mechanism applied thereto, and also relates to a method of operating the vehicle cruise control system. Background Art

[0002] Autonomous driving means that a car can independently complete driving requirements without the need for driver intervention. To achieve this goal, the Society of Automotive Engineers (SAE) will classify autonomous driving functions into six levels, from L0 to L5. The lower the degree of driver involvement in driving, the higher the level of autonomous driving.

[0003] In recent years, with the gradual improvement of commercial vehicle specifications, features such as ACC (Adaptive Cruise Control) have been gradually introduced. Adaptive cruise control, also known as active cruise control, is an upgrade from cruise control and an intelligent advanced driver assistance system. Adaptive cruise control (ACC) uses onboard sensors (such as radar) to monitor traffic conditions ahead (generally within 200 meters). Its braking logic is typically gentle. If the risk ahead increases to the point where AEB (Automatic Emergency Braking) is activated, strong braking is applied. AEB also has several levels. This approach is intended to prevent false triggering and frequent acceleration and deceleration. For example, if there is a vehicle cutting in ahead, the vehicle may initially be below the safe distance. However, if the distance between the two vehicles increases, meaning the vehicle ahead is faster than the vehicle, ACC will not be immediately triggered. If the safe distance is not exceeded after several seconds of increasing distance, the vehicle will gradually decelerate. Therefore, ACC involves gentle action within a short forward field of view.

[0004] ZF has proposed a Predictive Economic Cruise Control (PECC) system (OptiPace TM ), or Predictive Economic Cruise Control. PECC consists of three components: the vehicle positioning system, which uses GNSS (Global Navigation Satellite System) for precise positioning; the ADAS map, which matches GNSS-derived positioning information with the map to confirm the vehicle's position and obtain road ahead information; and the PECC system, based on this road ahead information, optimizes vehicle speed and coordinates the vehicle's actuator systems, ultimately achieving effective fuel savings, reduced maintenance costs, and less driver workload.

[0005] PECC is an optimization and improvement based on ACC. PECC can determine the slope at a long distance based on map information and thus perform acceleration and deceleration planning, i.e., speed planning.

[0006] Although adaptive cruise control is widely considered a key component of future self-driving cars, its application is still immature, and the difficulty lies in its adaptability. For example, in extreme situations such as special road conditions, the adaptive cruise control system does not work well. For example, during the research process of this invention, the inventors found that the existing technology has at least the following problems:

[0007] To ensure that the speed difference from the constant cruising speed is within a defined range, a preset speed range is embedded in the PECC. However, when faced with long downhill sections, this limitation can cause the vehicle to brake prematurely or frequently to reduce the speed to below the upper limit, as the initial speed before the downhill section is likely to be relatively high. In predictive cruise control systems, the vehicle receives terrain coordinates and / or terrain information within its forward field of view via a wireless network, via a server or cloud storage. This forward field of view is typically preset to a minimum of 3 km. However, with current forward field of view configurations, predictive cruise control systems struggle to anticipate "long downhill sections" ahead. For example, when a long downhill section is 5-8 km long with an average gradient of 2-3%, the inability to accurately predict the long downhill section can lead to premature or frequent braking. On a downhill section, when the speed reaches the predetermined upper limit, braking is activated. This can result in continuous or frequent braking for a period of time, leading to high temperatures in the retarder and / or brakes, and potentially causing brake restriction, temporary failure, or durability issues.

[0008] Summary of the Invention

[0009] In view of this, an embodiment of the present invention provides a predictive cruise control system for a vehicle, comprising: a forward terrain information acquisition device configured to acquire terrain information within a predetermined distance range on a road ahead of the vehicle during vehicle operation, the terrain information including at least the coordinates and slope of the road ahead; a mission planning device configured to plan vehicle operation control on the road ahead, the vehicle operation control including at least vehicle speed control and braking operation control; and an overspeed identification device configured to determine whether the vehicle's expected speed on the road ahead exceeds a predetermined protection range, the predetermined protection range being between a first speed and a second speed, the first speed being a predetermined lower speed limit and the second speed being a predetermined upper speed limit. When the acquired terrain information contains a downhill section, causing the expected vehicle speed to exceed the predetermined protection range, the mission planning device replans the vehicle's operation control to (i) temporarily extend the predetermined protection range or (ii) extend the interval between adjacent braking events.

[0010] Preferably, within a predetermined distance range of the vehicle's front field of view, a plurality of planning points for planning calculation are established corresponding to the driving route, the front terrain information acquisition device acquires terrain information of each of the planning points, the terrain information at least includes coordinate information and slope information of each planning point, the task planning device acquires vehicle information at each of the planning points, the vehicle information at least includes vehicle speed information and torque information, and the speeding identification device uses the terrain information and the vehicle information to make the judgment.

[0011] Preferably, when the planned point farthest from the vehicle among the multiple planned points is determined to be on a downhill section, the end point of the downhill section replaces the farthest planned point.

[0012] Preferably, when the planned point farthest from the vehicle among the multiple planned points is determined to be on a downhill section, the end point of the downhill section is added as the farthest planned point.

[0013] Preferably, the task planning device replans the operation control of the vehicle including: temporarily expanding the predetermined protection range so that before driving to the end of the downhill section, the predetermined protection range is between the third speed and the fourth speed, the third speed is the temporarily lowered predetermined vehicle speed lower limit value, and the fourth speed is the temporarily increased predetermined vehicle speed upper limit value.

[0014] Preferably, when the vehicle speed is greater than the second speed and less than or equal to the fourth speed, the vehicle performs a braking operation to reduce the vehicle speed to less than the second speed.

[0015] Preferably, when the vehicle reaches the end of the downhill section, the temporarily expanded speed range is released.

[0016] Preferably, the mission planning device replans the operational control of the vehicle, comprising: compared with the original braking operation plan, so as to achieve an earlier braking operation event before traveling to the end of the downhill section.

[0017] Preferably, the re-planning of the braking operation takes into account a reduction in peak temperature of brake components or a reduction in the expected driving time of the vehicle.

[0018] Preferably, the task planning device refers to the following equation to minimize the comprehensive optimization target f,

[0019] f=α*t+(1-α)*k*T,

[0020] Wherein, t is the expected expected travel time of the vehicle, α is a weighting factor of t, α∈(0,1), T is the peak temperature, and a proportional factor k is a metric parameter used to coordinate the order of travel time t and brake temperature T.

[0021] To achieve the above objectives, according to one aspect of an embodiment of the present invention, a method for controlling a braking operation of a vehicle used in a vehicle cruise control system is provided. The method comprises: acquiring terrain information within a predetermined distance range on a road expected to travel ahead of the vehicle while the vehicle is operating, the terrain information including at least the coordinates and slope of the road expected ahead; planning vehicle operation control on the road expected ahead, the vehicle operation control including at least vehicle speed control and braking operation control; and determining whether the expected vehicle speed on the road expected ahead exceeds a predetermined protection range, the predetermined protection range being between a first speed being a predetermined lower speed limit and a second speed being a predetermined upper speed limit. When the acquired terrain information includes a downhill section, causing the expected vehicle speed to exceed the predetermined protection range, replanning vehicle operation control to reduce the number of braking operations during a predetermined period of time while traveling on the downhill section.

[0022] To achieve the above objective, according to one aspect of an embodiment of the present invention, a vehicle is provided, which includes the predictive cruise control system according to an embodiment of the present invention.

[0023] To achieve the above object, according to one aspect of an embodiment of the present invention, a computer-readable medium is provided, on which a computer program is stored. When the program is executed by a processor, the method according to the embodiment of the present invention is implemented.

[0024] One embodiment of the above invention has the following advantages or beneficial effects. Specifically, by pre-planning the speed and braking schedule for downhill sections, the braking timing or frequency of the downhill sections can be improved, thereby avoiding continuous or frequent braking operations during the downhill sections. Consequently, high temperatures of the retarder and / or brake can be avoided, preventing or delaying the occurrence of issues leading to brake restriction, temporary failure, or durability issues.

[0025] The further effects of the above-mentioned non-conventional optional manner will be described below in conjunction with specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are provided for a better understanding of the present invention and are not intended to limit the present invention.

[0027] FIG1 is a schematic diagram according to an embodiment of the present invention, which shows the expansion of a planning point or the replacement of a planning point;

[0028] FIG2 is a system block diagram according to an embodiment of the present invention, which shows the main modules and architectural relationships included in the system;

[0029] FIG. 3 illustrates the input and output of an overspeed detector in a system according to an embodiment of the present invention.

[0030] FIG. 4 is a schematic diagram illustrating the effect of speed range expansion according to an embodiment of the present invention.

[0031] FIG. 5 is a schematic diagram illustrating a braking sequence and effect formed by distributing braking planning operations compared to an original braking event according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following description of exemplary embodiments of the present invention is made in conjunction with the accompanying drawings, in which various details of the embodiments of the present invention are included to facilitate understanding. These details should be considered as merely exemplary. Therefore, it should be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0033] According to one aspect of an embodiment of the present invention, a system for automatically controlling speed or vehicle braking in a cruise control system, an adaptive cruise control system or other cruise control system is provided. The operating system is preferably applied to the aforementioned PECC (OptiPace TM ) system. In the following description, for convenience, only the operation process and operation method in the "cruise system" are schematically described.

[0034] [Temporarily expand the speed tolerance range]

[0035] According to one aspect of the embodiments of the present invention, the predetermined speed range may be temporarily extended to address an overspeed phenomenon occurring on a long downhill slope due to an originally planned conventional speed plan.

[0036] FIG1 is a schematic diagram illustrating the expansion or replacement of planned points according to an embodiment of the present invention. Referring to FIG1 , a schematic diagram illustrating uphill and downhill vehicle travel is shown. The dark solid line represents a cross-sectional view of the travel route as viewed from the side. The left side of the figure shows a black truck schematic diagram. The actual vehicle is not limited to a truck and can be any type of road-going vehicle or utility, including an unmanned vehicle that utilizes driverless autonomous driving technology. Points A to B represent the vehicle's forward field of view. Points C to D schematically illustrate a downhill section, which exhibits an average slope (inclination) relative to a horizontal section. Points E to D schematically illustrate the post-downhill section from near the end of the downhill slope to the point where the vehicle completely enters a relatively flat road. The endpoint P of the downhill section is set in the first half of this section or approximately in the middle. In the area corresponding to the default forward field of view section AB, at least one (herein, multiple) preset points (hereinafter referred to as "planned points"), P1...Pn, for subsequent calculations are schematically illustrated. Note that the number of preset points can be configured using an adaptive number of points or by setting the interval between preset points to a constant.

[0037] When the vehicle is traveling forward, the cruise control system sets a predetermined cruising speed, for example, less than or equal to 60 kilometers per hour (km / h). This speed may be determined based on at least one of several factors, including fuel economy, vehicle safety, and local traffic regulations. While in cruise control, if the vehicle's speed gradually increases due to downhill inertia to a speed exceeding the predetermined cruise speed, for example, reaching 65 km / h, the cruise control system will initiate a warning or braking state in the background. As the speed reaches a protective upper limit, such as 80 km / h, the system will initiate protective braking to bring the vehicle back below the upper limit. At lower speeds, for example, below the cruise control speed, the cruise control system will apply positive torque and actively apply traction, accelerating the vehicle to achieve the predetermined cruising speed.

[0038] The cruise system (especially the PECC system) can obtain map information of the area and the surrounding areas of the driving section through wireless networks and / or satellite positioning, so as to know in advance the situation of the road section beyond a certain distance, such as whether it is an uphill or downhill section, so that the speed plan can be set in advance. In order to control the calculation cost, in this embodiment, the cruise system considers the limited front field of view after deletion, that is, the AB section in Figure 1. If the last preset point Pn is located in the downhill section (that is, the slope of the last location is a negative value), the cruise system can know when the downhill road ends by adding one or more planned points to the deleted front field of view or replacing the last planned point. Specifically, the last point Pn is deleted from the point set from P1 to Pn, and the more distant point is added to the existing point set as a new Pn point to replace the original Pn point. Referring to Figure 1, the distant point is the Pm point in the figure. Alternatively, a new point is added after the Pn point, that is, the Pm point. Note that according to this illustrative embodiment, whether to perform an append or replace operation can be determined based on the number of planned points in the point set P. For example, the threshold value of n is predetermined to be 25 (this value is an illustrative setting). When n≤25, a new point Pm can be added after the last planned point Pn in the point set (here the original Pn point is still retained). If the number of points n>25, then a replacement can be used, that is, the last point Pn in the original point set is deleted, and instead a more distant point, namely Pm, is added to the existing point set to replace the original Pn point.

[0039] The coordinates of all points from P1 to Pn and the slopes of all points are originally known in the cruise system. When the range of the planned point set is extended to point Pm by following one of the additional or alternative methods described above, the field of view of the planned route is increased. This means that the coordinates and slope of the new last point (Pm) have been changed compared to the coordinates and slope of the original last point (Pn). Specifically, in Figure 1, there is an average slope between the new planned point Pm (i.e., the last planned point) and the last road section before the new planned point Pm. The average slope is fed to the cruise system. Then, using the coordinates of all planned points, the slopes of all planned points, and the average slope of the last road section, the cruise system can perform mission planning to output the speed curve of all planned points in the field of view ahead (Figure 1).

[0040] In the cruise system according to the present embodiment, the current vehicle speed, the future coordinates of each planning point, the slope and cruising speed corresponding to the future coordinates of each planning point are received through the PECC planner described below (see FIG2 hereinafter), and future mission planning is performed using a dynamic programming algorithm and a corresponding cost function. Note that when planning, additional factors that need to be considered include but are not limited to vehicle fuel consumption, expected driving time, speed change rate, etc. The PECC planner outputs the results of the optimization calculation to the downstream program, wherein the output results include the future vehicle speed at each planning point in the field of view ahead. Note that since the vehicle is in actual continuous driving, the planning calculation results of future planning points can show dynamic changes.

[0041] FIG2 shows a schematic diagram of an adaptive navigation control system according to this embodiment. In FIG2 , 201 represents an overspeed identification device, which is used to check whether the speed exceeds a predetermined threshold. 202 represents a forward terrain information acquisition device, also known as an electronic horizon device (e-horizon), which is used to receive terrain information within the forward field of view via a wireless network via a server or cloud storage, wherein the terrain information includes the coordinates of the planned points of the road within the forward field of view and / or the slope information of the planned points, thereby providing a coordinate data set of the planned points of the road ahead. 203 represents a mission planning device, which is used to plan and control the vehicle speed based on the speed information of the road ahead, including at least one of increasing the vehicle speed, reducing the vehicle speed, and taking braking measures. 204 represents a speed curve generation device, which is used to generate a speed curve based on the output results of the mission planning.

[0042] Long downhill sections can cause the speed to increase continuously after entering the downhill slope. Because the mission planning device 203 only searches for speed values ​​within a preset range, an additional module—namely, the speeding detection device 201—is required to identify whether the speed is about to exceed the predetermined protection range. The speeding detection device 201 receives input values ​​from both the electronic horizon device 202 and the mission planning device 203 and uses these input values ​​to calculate basic vehicle dynamics in the longitudinal direction (see Figure 2). The mission planning device 203 generates a new planned mission and then outputs the new mission to the speed profile generation device 204 to generate a speed profile to control speed changes.

[0043] FIG3 shows the working mode of the overspeed identification device 201 in the system shown in FIG2 . As shown in the figure, the coordinates (301) of the planning point and the slope (302) of the planning point corresponding to the coordinates are received from the electronic horizon device 201. On the other hand, the speed information (303) of the planning point and the torque information (304) of the planning point are received from the PECC task planning device. Using the planned speed (303) at the last planned point (Pn) before the downhill section, the torque curve (304) from this point to the next point Pm, and the slope information 302 in this area of ​​interest, the speeds of multiple planned points in this area can be calculated (see FIG3 ).

[0044] Optionally, when the proportion of speeding situations within a travel section exceeds a certain threshold, an expansion trigger value is set to activate. For example, when speeding situations occur within 10% of the forward field of view or within 15% of a downhill slope, a speed range expansion operation is initiated, as indicated by the arrow pointing to 305 in FIG3 . When the speed range expansion operation is determined to be initiated, the mission planning device needs to re-plan speed using the temporarily expanded speed range.

[0045] Optionally, when the overspeed situation exceeds a certain threshold, the speed range expansion planning may not be performed, but the distributed braking planning may be activated (as shown in FIG. 5 below) as indicated by the arrow pointing to 306 in FIG. 3 .

[0046] The user can pre-select whether to use the speed range expansion operation mode or the distributed braking planning mode. For example, one of the above two operation modes can be embedded in the vehicle system during the vehicle manufacturing process or customization process. Optionally, the above two operation modes are built into the vehicle system at the same time, and before the vehicle is driven, the user can set either of the above two modes as the default mode. In the case where there are multiple different drivers who may share the same vehicle at different times, for example, if the driver is changed, different driving habits and preferences may be encountered. In this case, the new user (driver) can choose to use the speed range expansion operation mode or the distributed braking planning mode according to his or her preferences. For example, if the customer can accept a larger up / down speed limit in a short period of time, the speed range expansion mode (305) can be selected, otherwise a relatively smoother mode, namely the distributed braking planning mode (306), can be selected.

[0047] Alternatively, the speed range expansion mode or the distributed braking planning mode can be selected based on the speed limit information for the road ahead. In this mode, the speed limit information for the road ahead can be obtained through a cruise control system (e.g., PECC). If the upper speed limit value in the obtained speed limit information for the road ahead is lower than the expected upper speed limit after the expansion, the distributed braking planning mode can be selected.

[0048] FIG. 4 is a schematic diagram illustrating the effect of speed range expansion according to an embodiment of the present invention.

[0049] Referring to FIG4 (A), the conventional adaptive process is illustrated. Initially, the planned speed is within a predetermined speed range. As the vehicle enters the downhill section, it freewheels and accelerates, gradually increasing its speed. Upon reaching the upper limit of the predetermined speed range—time T1 in the figure—braking is initiated, limiting the vehicle speed to near the upper limit until the downhill section ends.

[0050] Referring to FIG4(B) below, according to this embodiment, the speed range is extended. Specifically, in the initial stage of entering a downhill section, the initial speed is allowed to decrease until it is below the desired speed range. Then, as the downhill section extends, the vehicle speed gradually increases while freely traveling, exceeds the desired speed range at the illustrated moment T2, enters the braking state after maintaining for a period of time, and then the vehicle speed gradually decreases. It is noted that in FIG4(B) below, since it is expected that the free sliding ahead will result in a greater acceleration, the torque output can be reduced in the section before the downhill. This makes the initial speed lower, which means that the moment (T4) when the vehicle speed reaches the upper limit of the predetermined speed range is later than the moment (T1) when the upper limit value is reached in FIG4(A) above.

[0051] Preferably, the speed range can be expanded bidirectionally, i.e., by raising the upper limit of the speed range and / or lowering the lower limit of the speed range. By increasing the upper limit and / or lower limit of the speed range in at least one of the two directions, the center of the planned speed range can be kept near the driver's desired cruising speed.

[0052] Preferably, the expanded speed range can be restored to the default speed range at an appropriate time, for example, after the vehicle reaches the end of a long downhill slope, or after a certain time has passed.

[0053] [Planning for decentralized braking events]

[0054] As described above, when the overspeed identification module determines that the overspeed situation exceeds a certain threshold, optionally, as indicated by the arrow pointing to 306 in FIG. 3 , it is determined to activate the decentralized braking plan.

[0055] FIG. 5 is a schematic diagram illustrating a braking sequence and effect formed by distributing braking planning operations compared to an original braking event according to an embodiment of the present invention.

[0056] According to one aspect of an embodiment of the present invention, dispersed braking events may be planned for long downhill slopes that may result in repeated or intensive braking situations due to an originally planned conventional plan.

[0057] As shown in FIG4(A), a speed range is set for the speed value, and the speed range is within the lower limit speed V 下限 and upper speed limit V 上限 Without expanding the speed range, when the actual vehicle speed increases to the upper speed limit V 上限 , the vehicle needs to automatically enter the braking state to keep the speed below the upper limit V 上限 . Accordingly, the upper panel 5(A) in FIG. 5 illustrates conventional braking behavior when the speed limit is reached. In FIG. 5(A), when the vehicle speed reaches the upper limit of the predetermined speed range, the control function in the adaptive control system is triggered, namely the first automatic braking operation B1. Note that due to the hysteresis of the braking function, the vehicle speed briefly exceeds the upper limit. As shown in FIG. 5(A), the speed curve exceeds the upper limit V of the speed range at B1. Then, with the braking function activated, the vehicle speed decreases below the upper limit, resulting in the termination of braking. Subsequently, due to the inertia of the downhill slope, the vehicle speed resumes its upward movement and again exceeds the upper limit. This triggers a braking operation in the adaptive control system, namely the second automatic braking operation shown at time B2 in the figure. After the vehicle speed decreases, the previous process repeats. That is, the vehicle speed continues to increase due to the inertia of the downhill slope, triggering the third automatic braking operation at time B3, causing the vehicle speed to return to within the predetermined speed range. The figure only illustrates three braking operations for illustration purposes; actual situations are not limited to three braking operations. As shown in the figure, during the braking process at the three time points B1, B2 and B3, the vehicle speed is within the upper limit V of the predetermined speed range. 上限 The area around the vehicle exhibits regular, periodic changes. Braking is repeated multiple times within a relatively short period of time.

[0058] FIG5(B) below shows the braking sequence under speed planning according to an embodiment of the present invention, compared to conventional braking operations. Referring to FIG5(B), three braking operations were also performed during downhill travel, namely, at braking operation time points B4, B5, and B6. However, unlike FIG5A, FIG5(A) shows multiple instances of speed exceeding the speed limit. In contrast, according to an embodiment of the present invention, as shown in FIG5(B), fewer instances of speeding were achieved.

[0059] In Figure 5(B), an endpoint PB is set, which corresponds to the predicted point where the vehicle can automatically decelerate without braking, and an upper speed limit is assigned at this point PB as one of the boundary conditions of the control strategy. The lower limit of braking deceleration is set separately. For example, if the upper speed limit is 90 km / h and the speed limit for overspeed is 92 km / h, it means that deceleration should be triggered when the vehicle speed reaches 92 km / h. The preset deceleration amount is 5 km / h, that is, the lower limit of deceleration is 87 km / h. The braking end point is set based on the lower limit of deceleration and the PB point. Specifically, from the PB point corresponding to the upper speed limit of 90 km / h to a specific point in time, when the vehicle speed is predicted to reach 87 km / h due to the position at that point in time, it can be increased to 90 km / h through free sliding. Furthermore, starting from point PA, based on the aforementioned inferred braking deceleration time required to decelerate from 92 km / h to 87 km / h, continue to backtrack in the direction opposite to the direction of travel (i.e., to the left in the figure). Preferably, the amount of deceleration in the subsequent backtracking process may be consistent with the last time, and the timing of braking is determined by a minimum time interval threshold (such as 20 seconds) and the PECC planning speed. Note that, optionally, the braking deceleration time is related to the braking depth, which is manually specified in the program. The greater the braking depth is set, the stronger the braking effect, and the braking deceleration time to achieve the deceleration amount is correspondingly shorter.

[0060] Note that if the lower speed limit of 87 km / h is reached during the backtracking process, the limited range of the planned speed range is reached, and the braking planning as described above is performed. In addition, if the speed of 87 km / h is not capped (i.e., less than 90 km / h), the backtracking continues until the time interval threshold is exceeded (i.e., for example, the aforementioned 20 seconds) or until the planned speed is greater than or equal to 90 km / h. Preferably, after all braking plans are completed, the plan at this time is used as the initial input, and several iterative calculations are performed to reduce the total braking amount, reduce the vehicle speed during braking, extend the braking interval time and increase the average vehicle speed, thereby obtaining the final braking planning result. Preferably, these four variables are used as optimization targets, and the cost function can be composed of the assigned weight ratios to perform optimization iterations.

[0061] As can be seen in Figure 5(B), the first braking operation (B4) occurs when the vehicle speed has not yet reached the predetermined speed range, i.e., earlier. After the braking effect is achieved, the vehicle speed decreases. Subsequently, due to the inertia of the downhill slope, the vehicle speed recovers, and after a certain period of time, the system triggers the second braking operation (B5). Note that the vehicle speed at this point is still below the upper limit of the speed range. After the second braking operation, the vehicle speed recovers and reaches the upper limit of the speed range, and then the third braking operation is initiated at time B6. The vehicle speed thus decreases below the upper limit of the speed range. Note that although three braking operations are performed here, the actual number of braking operations is not limited to three and can be more or less. Referring to Figure 5(B), because the first braking operation (B4) occurs earlier (earlier than time B1 in Figure 5A), the time interval between the third braking operation (B6) that reaches the upper limit and the preceding braking operation (B5) is longer, specifically longer than the time interval between B2 and B3 shown in Figure 5(A). Therefore, Figure 5(B) achieves earlier braking and more dispersed repeated braking operations.

[0062] According to this embodiment, by implementing the first braking action earlier and distributing multiple braking operations more widely, beneficial effects are achieved. For example, due to the lower braking speed, less heat is generated in the brake or retarder components. Furthermore, due to the longer intervals between braking events, the brake components can be better cooled, thereby helping to maintain the lifespan and continued effectiveness of the brake or retarder. Furthermore, in some situations, it is anticipated that fewer braking events may be required. For example, compared to the three braking events shown in Figure 5(A), the desired braking effect can actually be achieved with one or two braking events.

[0063] Furthermore, in the process of optimizing the timing and number of braking events, the peak temperature of the retarder / foundation brake and the expected travel time of the vehicle are used as optimization targets.

[0064] Single objective optimization can use the weighting factor of travel time t, α∈(0,1) to simplify the problem of multi-objective optimization. Therefore, the current optimization problem is to minimize the comprehensive optimization objective f, that is, satisfy the following equation,

[0065] f=α*t+(1-α)*k*T.

[0066] In this case, the scaling factor k is used to reconcile different measures of the order of the expected travel time t and the brake temperature T.

[0067] These two factors, i.e., desired travel time t and brake temperature T, can be adjusted according to user (or driver) preferences, depending in part on whether the user wants to optimize brake (retarder) durability by controlling to reduce brake temperature, or optimize driving (transportation) efficiency by reducing travel time t. It should be noted that the time lost in limited durability is not always critical.

[0068] As previously mentioned, according to various aspects of the present invention, predictive control of braking operations and braking events is achieved by 1) temporarily expanding the speed limit range or 2) optimizing / distributing braking timing. By distributing braking operations more widely, the timing and frequency of braking events are optimized, thereby reducing brake aging, lowering brake failure rates, and extending brake life (brakes include hydraulic retarders and brake discs).

[0069] The above-mentioned cruise control system can be applied in a vehicle so that when the vehicle is traveling downhill, the vehicle speed and braking operation are planned and controlled by the control device contained in the vehicle itself, thereby realizing various functions and effects of the above-mentioned cruise control system.

[0070] The cruise control system described above is not limited to being constructed and implemented by the aforementioned physical components, but can be implemented by any component that possesses the necessary functionality. In other words, the various functions and effects of the cruise control system described above can be achieved by completing the steps or processes associated with the functions of each component (device).

[0071] As another aspect, the present invention further provides a computer-readable medium, which may be included in the device described in the above embodiment; or it may exist independently without being assembled into the device. The above-mentioned computer-readable medium carries one or more programs, and when the above-mentioned one or more programs are executed by one of the devices, the device performs the functions included in the aforementioned system or the steps included in the method. In particular, according to the embodiments disclosed in the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present invention include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication part, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), the above-mentioned functions defined in the system of the present invention are executed.

[0072] It should be noted that the computer-readable medium described in the present invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media can include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. This propagated data signal can take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber cable, RF, or any suitable combination thereof.

[0073] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, as well as the combination of boxes in the block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or can be implemented using a combination of dedicated hardware and computer instructions.

[0074] The units involved in the embodiments of the present invention may be implemented in software or hardware. The units described may also be provided in a processor. The names of these units do not, in certain circumstances, limit the units themselves.

[0075] As another aspect, the present invention further provides a computer-readable medium, which may be included in the device described in the above embodiments, or may exist independently and not incorporated into the device. The computer-readable medium carries one or more programs, which, when executed by the device, cause the device to: obtain vehicle operation-related information; optimize the vehicle's speed profile based on the vehicle operation-related information; and, based on the optimized speed profile, predict the optimal gear position for an automated manual transmission (AMT) and assist in AMT shift control.

[0076] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

[0077] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A predictive cruise control system for a vehicle, comprising: a forward terrain information acquisition device configured to acquire, while the vehicle is running, terrain information within a predetermined distance range on a road ahead of the vehicle that is expected to travel, the terrain information including at least the coordinates and slope of the road ahead that is expected to travel; a mission planning device configured to plan operation control of the vehicle on the expected forward travel path, wherein the operation control of the vehicle includes at least vehicle speed control and brake operation control; an overspeed identification device configured to determine whether an expected speed of the vehicle on the expected driving road ahead exceeds a predetermined protection range, the predetermined protection range being between a first speed and a second speed, the first speed being a predetermined lower speed limit and the second speed being a predetermined upper speed limit; When the acquired terrain information includes a downhill section and the expected vehicle speed exceeds the predetermined protection range, the mission planning device replans the operation control of the vehicle so as to: (i) temporarily extend the scope of protection; or (ii) Extend the interval between adjacent braking events.

2. The predictive cruise control system according to claim 1, wherein: A plurality of planning points for planning calculation are established corresponding to the driving route within a predetermined distance range of the front field of view of the vehicle, The forward terrain information acquisition device acquires terrain information of each of the planned points, wherein the terrain information at least includes coordinate information and slope information of each of the planned points. The mission planning device obtains vehicle information at each planning point, wherein the vehicle information includes at least vehicle speed information and torque information, and The speeding identification device makes the determination using the terrain information and the vehicle information.

3. The predictive cruise control system according to claim 2, wherein: When the planned point farthest from the vehicle among the multiple planned points is determined to be on a downhill section, the farthest planned point is replaced by an end point of the downhill section.

4. The predictive cruise control system according to claim 2, wherein: When the planned point farthest from the vehicle among the multiple planned points is determined to be in a downhill section, the end point of the downhill section is added as the updated farthest planned point.

5. The predictive cruise control system according to claim 1, wherein: The task planning device replans the operation control of the vehicle, including: temporarily extending the predetermined protection range so that before traveling to the end of the downhill section, the predetermined protection range is between a third speed and a fourth speed, the third speed is a temporarily lowered predetermined vehicle speed lower limit value, and the fourth speed is a temporarily increased predetermined vehicle speed upper limit value.

6. The predictive cruise control system according to claim 5, wherein: When the vehicle speed is greater than the second speed and less than or equal to the fourth speed, the vehicle performs a braking operation to reduce the vehicle speed to less than the second speed.

7. The predictive cruise control system according to claim 5, wherein: When the vehicle reaches the end of the downhill section, the temporarily expanded speed range is released.

8. The predictive cruise control system of claim 1, wherein: The mission planning device replans the operational control of the vehicle, including: compared with the original braking operation plan, so as to achieve an earlier braking operation event before driving to the end of the downhill section.

9. The predictive cruise control system according to claim 8, wherein: Reducing the peak temperature of brake components or reducing the expected travel time of the vehicle is taken into account in the replanning of the braking operation.

10. The predictive cruise control system of claim 10, wherein: The task planning device refers to the following equation to minimize the comprehensive optimization target f, f=α*t+(1-α)*k*T, Wherein, t is the expected expected travel time of the vehicle, α is a weighting factor of t, α∈(0,1), T is the peak temperature, and a proportional factor k is a metric parameter used to coordinate the order of travel time t and brake temperature T.

11. A braking operation control method for a vehicle used in a vehicle cruise control system, the method comprising: Acquiring terrain information within a predetermined distance range on a road expected to be driven ahead of the vehicle while the vehicle is running, the terrain information including at least coordinates and a slope of the road expected to be driven ahead; Planning operation control of the vehicle on the expected forward travel road, the vehicle operation control including at least vehicle speed control and brake operation control; determining whether an expected speed of the vehicle on the expected forward travel road exceeds a predetermined protection range, the predetermined protection range being between a first speed and a second speed, the first speed being a predetermined lower speed limit and the second speed being a predetermined upper speed limit; When the acquired terrain information includes a downhill section and the expected vehicle speed exceeds the predetermined protection range, the vehicle operation control is replanned so as to: (i) temporarily extend the scope of protection; or (ii) Extend the interval between adjacent braking events.

12. The method according to claim 11, wherein A plurality of planning points for planning calculation are established corresponding to the driving route within a predetermined distance range of the front field of view of the vehicle, The forward terrain information acquisition device acquires terrain information of each of the planned points, wherein the terrain information at least includes coordinate information and slope information of each of the planned points. The mission planning device obtains vehicle information at each planning point, wherein the vehicle information includes at least vehicle speed information and torque information, and The speeding identification device makes the determination using the terrain information and the vehicle information.

13. The method according to claim 12, wherein: When the planned point farthest from the vehicle among the multiple planned points is determined to be on a downhill section, the farthest planned point is replaced by an end point of the downhill section.

14. The method according to claim 12, wherein: When the planned point farthest from the vehicle among the multiple planned points is determined to be on a downhill section, the end point of the downhill section is added as the farthest planned point.

15. The method according to claim 11, wherein The task planning device replans the operation control of the vehicle, including: temporarily extending the predetermined protection range so that before traveling to the end of the downhill section, the predetermined protection range is between a third speed and a fourth speed, the third speed is a temporarily lowered predetermined vehicle speed lower limit value, and the fourth speed is a temporarily increased predetermined vehicle speed upper limit value.

16. The method according to claim 15, wherein When the vehicle speed is greater than the second speed and less than or equal to the fourth speed, the vehicle performs a braking operation to reduce the vehicle speed to less than the second speed.

17. The method according to claim 15, wherein: When the vehicle reaches the end of the downhill section, the temporarily expanded speed range is released.

18. The method according to claim 11, wherein The mission planning device replans the operational control of the vehicle, including: compared with the original braking operation plan, so as to achieve an earlier braking operation event before driving to the end of the downhill section.

19. The method according to claim 19, wherein: Reducing the peak temperature of brake components or reducing the expected travel time of the vehicle is taken into account in the replanning of the braking operation.

20. The method according to claim 19, wherein The task planning device refers to the following equation to minimize the comprehensive optimization target f, f=α*t+(1-α)*k*T, Wherein, t is the expected expected travel time of the vehicle, α is a weighting factor of t, α∈(0,1), T is the peak temperature, and a proportional factor k is a metric parameter used to coordinate the order of travel time t and brake temperature T.

21. A vehicle comprising a predictive cruise control system according to any one of claims 1-10.

22. A computer-readable medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 11 to 20 is implemented.

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