A predictive cruise and speed limit coordinated control method and device

Abstract

This invention provides a method and apparatus for coordinated control of predictive cruise and speed limit, comprising: adjusting the upper and lower limits of predictive cruise speed based on road congestion level, road gradient information, and the current cruise speed to obtain corrected predictive cruise speed upper and lower limits; calculating a predicted braking speed based on a comparison between a predicted speed sequence for coasting downhill in neutral and the coordinated speed limit values; calculating the predictive cruise speed, predictive cruise gear, and predictive cruise gear control state based on the corrected predictive cruise speed upper and lower limits and the predicted braking speed; adjusting the cruise demand torque based on a comparison between the actual speed and the speed limit and the predicted cruise speed to obtain a corrected cruise demand torque; and determining the calculation method for the speed limit demand torque based on the predictive cruise mode and the corrected cruise demand torque. The method provided by this invention achieves coordinated control of predictive cruise and speed limit.

Description

Technical Field

[0001] This invention relates to the field of vehicle speed control technology, and in particular to a predictive cruise and speed limit coordinated control method and device. Background Technology

[0002] Tractor vehicles with a maximum speed of 90 km / h or higher should be equipped with four relevant safety features: steering wheel disc brakes, Electronic Braking System (EBS), Automatic Emergency Braking System (AEBS), and run-flat tire emergency devices. If these safety features are incomplete, the vehicle's speed will be limited to 89 km / h. Currently, in both free-driving and cruise control modes, the speed limiting function uses PID control to adjust the speed-limiting torque, then takes the smaller of the throttle torque and cruise torque to output the required torque. At the critical speed limit point, torque fluctuations and consequently engine speed fluctuations are prone to occur. Given the high proportion of fuel costs in commercial vehicle operating costs, fuel efficiency control is crucial. Predictive cruise control, by considering road gradient information, allows speed fluctuations within a certain range and fully utilizes the vehicle's kinetic energy and the road's potential energy, effectively avoiding fuel-inefficient driving behaviors.

[0003] Currently, predictive cruise control achieves fuel savings when using low cruise speeds and positive torque on inclines without interfering with the speed limit torque. However, during inclines at low cruise speeds, the vehicle speed may deflect downwards, potentially causing cruise control to retract. At high cruise speeds, the high speed at the end of braking when transitioning from downhill to uphill can cause interference with the speed limit, resulting in reduced fuel economy. Therefore, coordinated control of predictive cruise control and speed limit is crucial for maximizing fuel efficiency while ensuring safety. Existing technologies typically use the smaller of the predicted cruise torque and the speed limit torque, followed by torque filtering during internal torque coordination mode switching; however, there is currently no research on coordinated control of predictive cruise control and speed limit.

[0004] How to achieve coordinated control of predictive cruise and speed limit is a technical problem that needs to be solved. Summary of the Invention

[0005] This invention provides a predictive cruise and speed limit coordinated control method and apparatus to address the deficiencies in the prior art.

[0006] This invention provides a method for coordinated control of predictive cruise and vehicle speed limit, comprising the following steps:

[0007] Based on the degree of road congestion, road gradient information, and the current cruise speed, the upper and lower limits of the predictive cruise speed are adjusted to obtain the corrected upper and lower limits of the predictive cruise speed. The predicted braking speed is calculated by comparing the predicted speed sequence based on coasting downhill in neutral with the coordinated speed limit.

[0008] Based on the corrected upper and lower limits of the predictive cruise speed and the predicted braking speed, the predictive cruise speed, the predictive cruise gear, and the predictive cruise gear control state are calculated; wherein, the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising.

[0009] Based on the comparison between the actual vehicle speed and the speed limit, and the predicted cruise speed, the cruise torque demand is adjusted to obtain the corrected cruise torque demand.

[0010] Based on the predictive cruise mode and the corrected cruise demand torque, the calculation method for the speed limit demand torque is determined, and the speed limit demand torque is calculated according to the determined calculation method.

[0011] According to the predictive cruise and speed limit coordinated control method provided by the present invention, the step of adjusting the upper and lower limits of the predictive cruise speed based on the degree of road congestion, road gradient information, and the current cruise speed to obtain the corrected upper and lower limits of the predictive cruise speed includes:

[0012] The original speed limit is adjusted based on the degree of road congestion, road slope, and road curvature to obtain a coordinated speed limit.

[0013] The minimum value between the coordinated speed limit and the predictive cruise speed limit is used as the corrected predictive cruise speed limit.

[0014] According to the predictive cruise and speed limit coordinated control method provided by the present invention, the step of adjusting the upper and lower limits of the predictive cruise speed based on the degree of road congestion, road gradient information, and the current cruise speed to obtain the corrected upper and lower limits of the predictive cruise speed includes:

[0015] The lower limit of the predictive cruise speed is adjusted based on the current cruise speed to obtain the corrected lower limit of the predictive cruise speed.

[0016] Where the current cruise speed is less than a preset speed threshold, the correction coefficient corresponding to the current cruise speed is negatively correlated with the current cruise speed.

[0017] According to the present invention, a predictive cruise and speed limit coordinated control method is provided, wherein the step of calculating the predicted braking speed based on the comparison result of the predicted vehicle speed sequence during coasting downhill in neutral and the coordinated vehicle speed limit value includes:

[0018] If the next uphill is a short uphill with a slope length less than the preset slope length, and there is a first target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the coordinated vehicle speed limit, then when the vehicle is engaged in gear and braked at the first target position point, and the actual vehicle speed remains at the coordinated vehicle speed limit value, then coasting in gear is used for this downhill.

[0019] or,

[0020] If the next uphill slope is a long uphill slope with a gradient greater than or equal to the preset slope length, and there is a second target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the sum of the coordinated speed limit and the drift threshold, then engage gear and brake at the second target position point, and the actual vehicle speed is maintained at the coordinated speed limit plus the drift threshold.

[0021] According to a predictive cruise and speed limit coordinated control method provided by the present invention, the step of adjusting the cruise demand torque based on the comparison result of the actual vehicle speed and the speed limit and the predictive cruise speed to obtain the corrected cruise demand torque includes:

[0022] The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the first demand torque. The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the intermediate demand torque. The intermediate demand torque is added to the cruise demand torque before correction to obtain the second demand torque.

[0023] The minimum value between the first required torque and the second required torque is determined as the corrected cruise required torque.

[0024] The cruise demand torque change rate correction coefficient is calculated based on the difference between the actual vehicle speed and the speed limit. If the difference is within the correction threshold range, the value of the cruise demand torque change rate correction coefficient is 1; otherwise, the cruise demand torque change rate correction coefficient is negatively correlated with the difference.

[0025] According to the predictive cruise and speed limit coordinated control method provided by the present invention, the torque correction coefficient can be obtained by the following calculation method:

[0026] If the actual torque and the required torque change at the same rate, the torque correction factor is set to 1; otherwise, the quotient of the actual torque and the required torque is added to 1 and the result is used as the torque correction factor.

[0027] According to a predictive cruise and speed limit coordinated control method provided by the present invention, the step of determining the calculation method of the speed limit demand torque based on the predictive cruise mode and the modified cruise demand torque, and calculating the speed limit demand torque according to the determined calculation method, includes:

[0028] When the predictive cruise mode is map valid and the corrected cruise demand torque is positive, the corrected cruise demand torque is used as the vehicle speed limit demand torque.

[0029] or,

[0030] When the predictive cruise mode is in the case of an invalid map or when the vehicle is not in cruise mode, the required torque for the vehicle speed limit is calculated by PID control based on the actual vehicle speed and the speed limit.

[0031] According to the predictive cruise and speed limit coordinated control method provided by the present invention, the step of calculating the speed limit demand torque based on the actual vehicle speed and the speed limit using PID control includes:

[0032] The target correction coefficient is obtained by multiplying the first correction coefficient corresponding to the driving style, the second correction coefficient corresponding to the road slope, and the third correction coefficient corresponding to the road curvature.

[0033] The actual vehicle speed calculated by the PID control is corrected based on the target correction coefficient.

[0034] Wherein, the target correction coefficient is negatively correlated with the vehicle speed deviation value; the first correction coefficient is negatively correlated with the degree of aggressive driving; the second correction coefficient is positively correlated with the road slope value; the third correction coefficient is positively correlated with the road curvature; and the vehicle speed deviation value is the difference between the limited vehicle speed and the actual vehicle speed calculated by the PID control.

[0035] The present invention also provides a predictive cruise and speed limit coordinated control device, comprising the following modules:

[0036] The first calculation module is used to adjust the upper and lower limits of the predictive cruise speed based on the degree of road congestion, road slope information and the current cruise speed, to obtain the corrected upper and lower limits of the predictive cruise speed, and to calculate the predicted braking speed based on the comparison results of the predicted speed sequence of coasting downhill in neutral and the coordinated speed limit value.

[0037] The second calculation module is used to calculate the predictive cruise speed, predictive cruise gear, and predictive cruise gear control state based on the corrected predictive cruise speed upper and lower limits and the predictive braking speed; wherein the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising.

[0038] The adjustment module is used to adjust the cruise demand torque based on the comparison result between the actual vehicle speed and the limited vehicle speed and the predicted cruise speed, so as to obtain the corrected cruise demand torque.

[0039] The third calculation module is used to determine the calculation method of the speed limit torque based on the predictive cruise mode and the corrected cruise torque, and to calculate the speed limit torque according to the determined calculation method.

[0040] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the predictive cruise and speed limit coordinated control method as described above.

[0041] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the predictive cruise and speed limit cooperative control method as described above.

[0042] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the predictive cruise and speed limit cooperative control method as described above.

[0043] This invention provides a predictive cruise and speed limit coordinated control method and apparatus. The method involves adjusting the upper and lower limits of the predictive cruise speed based on road congestion levels, road gradient information, and the current cruise speed to obtain corrected predictive cruise speed limits. It also involves calculating the predicted braking speed based on a comparison between the predicted speed sequence during coasting downhill in neutral and the coordinated speed limit values. Based on the corrected predictive cruise speed limits and the predicted braking speed, the method calculates the predictive cruise speed, predictive cruise gear, and predictive cruise gear control state. The predictive cruise gear and the predictive cruise gear control state are used to control the gear position during vehicle cruise. The method adjusts the cruise torque demand based on a comparison between the actual speed and the speed limit, and the predicted cruise speed, to obtain a corrected cruise torque demand. Finally, based on the predictive cruise mode and the corrected cruise torque demand, the method for calculating the speed limit torque demand is determined, and the speed limit torque demand is calculated according to the determined method. Therefore, this invention achieves coordinated control of predictive cruise and speed limit, thereby improving the fuel-saving effect of predictive cruise. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a flowchart illustrating the predictive cruise and speed limit coordinated control method provided by the present invention.

[0046] Figure 2 This is a complete flowchart of the predictive cruise and speed limit coordinated control method provided by the present invention.

[0047] Figure 3 This is a schematic diagram of the predictive cruise and speed limit coordinated control device provided by the present invention.

[0048] Figure 4 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] The following is combined with Figures 1-4 This invention describes a predictive cruise and speed limit coordinated control method and apparatus.

[0051] It should be noted that currently, there is no existing technology researching the coordinated control of predictive cruise and speed limit. Generally, the smaller of the predicted cruise torque demand and the speed limit torque demand is taken, and then torque demand filtering is performed during internal torque coordination mode switching. Current technical solutions have the following drawbacks: 1) Interference exists between the torque calculated for the maximum speed in predictive cruise and the torque calculated for the traditional speed limit, leading to engine speed fluctuations; 2) The predictive cruise downhill braking torque calculation does not consider the speed limit situation on the next uphill section, resulting in exceeding the speed limit and subsequent engine speed fluctuations; 3) The predicted cruise maximum speed limit does not consider the influence of driver style; 4) The predicted cruise maximum speed limit does not consider the influence of road congestion; 5) During low-speed cruise, the lower limit of the predicted cruise speed is a single calibrated value, and different vehicle models may experience cruise reversal. Based on this, the present invention provides a method for the coordinated control of predictive cruise and speed limit to solve at least one of the above problems.

[0052] Figure 1 This is a flowchart illustrating the predictive cruise and speed limit coordinated control method provided by the present invention, as shown below. Figure 1 As shown, the method includes the following:

[0053] Step 100: Adjust the upper and lower limits of the predictive cruise speed based on the degree of road congestion, road gradient information, and the current cruise speed to obtain the corrected upper and lower limits of the predictive cruise speed. Calculate the predicted braking speed based on the comparison between the predicted speed sequence for coasting downhill in neutral and the coordinated speed limit values.

[0054] Figure 2 This is a complete flowchart of the predictive cruise and speed limit cooperative control method provided by the present invention. The following is a summary of the process. Figure 2 The predictive cruise and speed limit coordinated control method provided by this invention will be fully described.

[0055] Specifically, step 100 adjusts the upper and lower limits of the predictive cruise speed based on the degree of road congestion, road gradient information, and the current cruise speed, to obtain the corrected upper and lower limits of the predictive cruise speed, including:

[0056] Step 110: Adjust the original speed limit based on the degree of road congestion, road slope, and road curvature to obtain a coordinated speed limit.

[0057] Step 120: Take the minimum value between the coordinated speed limit and the predictive cruise speed limit as the corrected predictive cruise speed limit.

[0058] Step 130: Adjust the lower limit of the predictive cruise speed based on the current cruise speed to obtain the corrected lower limit of the predictive cruise speed.

[0059] Where the current cruise speed is less than a preset speed threshold, the correction coefficient corresponding to the current cruise speed is negatively correlated with the current cruise speed.

[0060] In one embodiment, the calculation method for the coordinated vehicle speed limit and the coordinated vehicle speed upper and lower limits is explained.

[0061] The coordinated speed limit is calculated using the following formula:

[0062]

[0063] in, This indicates that the vehicle speed limit will be coordinated. This indicates the original speed limit.

[0064] This indicates the speed limit correction factor based on driver style. When the driver style is mild and cautious, the speed limit correction factor is 1, meaning the default calibration follows the mild and cautious model. When the driver style is aggressive, the speed limit correction factor increases according to the degree of aggression, and the deviation threshold between the actual speed and the speed limit decreases accordingly. In other words, when the driver style is aggressive, the degree to which the actual speed approaches the speed limit is allowed to be higher.

[0065] This indicates the speed limit correction factor based on the road congestion level and gradient. When the road congestion level is "congested," the speed limit correction factor is 1, meaning the default calibration is based on severe road congestion, and no speed limit correction is made to ensure safety. When the road congestion level is "clear" and the gradient is determined to be uphill, the speed limit correction factor increases with the gradient, and the deviation threshold between the actual speed and the speed limit decreases as the gradient increases. In other words, under predictive cruise control, in clear road conditions and uphill conditions, the degree to which the actual speed approaches the speed limit is higher; this is because predictive cruise control requires a decreasing cruise speed during uphill phases.

[0066] This indicates the speed limit correction factor based on the curvature of the road congestion level. When the road congestion level is "congested," the speed limit correction factor is 1, meaning the default calibration is based on severe congestion, and no speed limit correction is made to ensure safety. When the road congestion level is "clear" and the curvature indicates a turn, the speed limit correction factor decreases with the curvature, and the deviation threshold between the actual speed and the speed limit increases with the curvature. In other words, under predictive cruise control, in clear road conditions, the degree to which the actual speed approaches the speed limit is lower during turns.

[0067] The upper and lower limits of the coordinated vehicle speed are calculated according to the following formula:

[0068]

[0069] in, This represents the revised predictive cruise speed limit; it is obtained by taking the smaller of the original predictive cruise speed limit and the revised speed limit. This indicates the pre-correction upper limit of the predictive cruise speed. This indicates the revised speed limit.

[0070]

[0071] in, This represents the revised lower limit of the predictive cruise speed; it is obtained by multiplying the original lower limit of the predictive cruise speed by a correction factor based on the cruise speed. This indicates the lower limit of the predictive cruise speed before the correction. This indicates that the cruise speed lower limit is adjusted based on the cruise speed. When the cruise speed is lower than the threshold, the cruise speed lower limit adjustment coefficient gradually increases. The purpose is to improve the predictive cruise speed lower limit and avoid frequent cruise control retraction when different models are matched with low cruise speeds.

[0072] Specifically, step 100 calculates the predicted braking speed based on the comparison between the predicted vehicle speed sequence during coasting downhill in neutral and the coordinated vehicle speed limit value, including:

[0073] If the next uphill is a short uphill with a slope length less than the preset slope length, and there is a first target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the coordinated vehicle speed limit, then when the vehicle is engaged in gear and braked at the first target position point, and the actual vehicle speed remains at the coordinated vehicle speed limit value, then coasting in gear is used for this downhill.

[0074] or,

[0075] If the next uphill slope is a long uphill slope with a gradient greater than or equal to the preset slope length, and there is a second target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the sum of the coordinated speed limit and the drift threshold, then engage gear and brake at the second target position point, and the actual vehicle speed is maintained at the coordinated speed limit plus the drift threshold.

[0076] Furthermore, the calculation method for the predicted braking speed is explained.

[0077] 1) Calculate the predicted vehicle speed sequence {v1,v2,v3,...,vn} for coasting downhill in neutral; the predicted vehicle speed sequence for coasting downhill in neutral is obtained by calculation based on vehicle dynamics formulas.

[0078] If the predicted speed sequence {v1,v2,v3,...,vn} for the next uphill is a short uphill and coasting downhill in neutral has a point where it is greater than the coordinated speed limit, then at that point, the vehicle should be engaged in gear and braked to keep the actual speed at the coordinated speed limit. In this case, coasting downhill in gear will be used.

[0079] When coasting in gear, the predicted downhill vehicle speed sequence {v1,v2,v3,...,vn} is calculated according to the vehicle dynamics formula for coasting in gear to obtain {v11,v21,v31,...,vn1}.

[0080] 2) When the next uphill is a long uphill and the predicted speed sequence {v1,v2,v3,...,vn} for coasting downhill in neutral has a position point where the speed is greater than the coordinated speed limit plus the drift threshold, then engage the gear and brake at that position point to keep the actual speed at the coordinated speed limit plus the drift threshold.

[0081] It should be noted that the drift threshold refers to the upward offset of the coordinated speed limit. If the predicted downhill speed sequence {v1,v2,v3,...,vn} for coasting in neutral on a long uphill slope has a point greater than the coordinated speed limit plus the drift threshold, it indicates that the next uphill slope is long and the vehicle is coasting in gear. In this case, the speed limit can be appropriately relaxed, ideally without speed restrictions before the next long uphill slope, allowing all downhill kinetic energy to be converted into potential energy for the next uphill slope. The coordinated speed limit plus the drift threshold should be less than the maximum speed under downhill braking capacity. The maximum speed under downhill braking capacity is the maximum stable speed the vehicle can achieve based on its configuration, assuming the in-cylinder brake fluid and other braking capabilities are all engaged.

[0082] It should be noted that the above steps are calculated when the road congestion level is not congested; when the road congestion level is congested, downhill braking is performed by coasting in gear and the driver is reminded to pay attention to road conditions and apply the brakes in time to exit cruise control.

[0083] Step 200: Based on the corrected upper and lower limits of the predictive cruise speed and the predicted braking speed, calculate the predictive cruise speed, the predictive cruise gear, and the predictive cruise gear control state; wherein, the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising.

[0084] Specifically, predictive cruise speed, predictive cruise gear, and predictive cruise gear control state are calculated using model predictive control methods.

[0085] Step 300: Adjust the cruise demand torque based on the comparison results of the actual vehicle speed and the limited vehicle speed and the predicted cruise speed to obtain the corrected cruise demand torque.

[0086] Specifically, step 300 includes:

[0087] Step 310: Adjust the cruise demand torque before correction based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the first demand torque; adjust the cruise demand torque before correction based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the intermediate demand torque; and add the intermediate demand torque to the cruise demand torque before correction to obtain the second demand torque.

[0088] Step 320: Determine the minimum value between the first required torque and the second required torque as the corrected cruise required torque;

[0089] The cruise demand torque change rate correction coefficient is calculated based on the difference between the actual vehicle speed and the speed limit. If the difference is within the correction threshold range, the value of the cruise demand torque change rate correction coefficient is 1; otherwise, the cruise demand torque change rate correction coefficient is negatively correlated with the difference.

[0090] In one embodiment, the method for calculating the cruise torque requirement is explained.

[0091] The required torque for cruising is calculated using the following formula:

[0092]

[0093] in, This indicates the corrected cruise torque requirement. This indicates the cruise torque requirement before the correction.

[0094] This represents the correction factor for the rate of change of cruise torque demand, calculated based on the difference between the actual vehicle speed and the speed limit. If the difference is outside the correction threshold range, the correction factor is 1, indicating no correction is needed. If the difference is within the correction threshold range, the correction factor is applied in the opposite direction to the difference. In other words, the smaller the difference between the actual vehicle speed and the speed limit, the larger the correction factor for the rate of change of cruise torque demand, preventing engine speed fluctuations due to exceeding the speed limit.

[0095] This represents the torque correction factor obtained from the actual torque to indicate the cruise torque requirement. When the actual torque and the required torque change at the same rate, this torque correction factor is 1 and there is no correction. When the actual torque and the required torque change at different rates, this torque correction factor is calculated as follows:

[0096]

[0097] Step 400: Based on the predictive cruise mode and the corrected cruise demand torque, determine the calculation method for the speed limit demand torque, and calculate the speed limit demand torque according to the determined calculation method.

[0098] Specifically, step 400 includes:

[0099] Step 410: When the predictive cruise mode is map valid and the corrected cruise demand torque is positive, the corrected cruise demand torque is used as the vehicle speed limit demand torque.

[0100] or,

[0101] Step 420: When the predictive cruise mode is in the case of map invalidation or the vehicle is not in cruise mode, the speed limit torque is calculated by PID control based on the actual vehicle speed and the speed limit.

[0102] Step 420 specifically includes:

[0103] Step 421: Calculate the product of the first correction coefficient corresponding to the driving style, the second correction coefficient corresponding to the road slope, and the third correction coefficient corresponding to the road curvature to obtain the target correction coefficient.

[0104] Step 422: Correct the actual vehicle speed calculated by the PID control based on the target correction coefficient;

[0105] Wherein, the target correction coefficient is negatively correlated with the vehicle speed deviation value; the first correction coefficient is negatively correlated with the degree of aggressive driving; the second correction coefficient is positively correlated with the road slope value; the third correction coefficient is positively correlated with the road curvature; and the vehicle speed deviation value is the difference between the limited vehicle speed and the actual vehicle speed calculated by the PID control.

[0106] In one embodiment, the method for calculating the torque required for vehicle speed limits is explained.

[0107] The torque required for vehicle speed limits should be selected as follows:

[0108] When the predictive cruise mode is active and the cruise torque requirement is positive, the speed limit torque requirement is selected based on the cruise torque requirement. When the predictive cruise mode is inactive or not in cruise mode, the speed limit torque requirement is calculated using adaptive PID control based on the actual vehicle speed and the speed limit.

[0109] The adaptive PID torque control, based on actual vehicle speed and speed limit, corrects the PID coefficients and threshold according to the following formula:

[0110]

[0111] This represents the correction factor for calculating the PID coefficient and threshold of the speed limit torque based on driver style. When the driver style is mild and cautious, the correction factor for calculating the PID coefficient and threshold of the speed limit torque is 1, meaning the default calibration is based on the mild and cautious type. When the driver style is aggressive, the correction factor for the PID coefficient change in the speed limit torque calculation decreases according to the degree of aggressiveness of the driver style, and the correction factor for the deviation threshold between the actual vehicle speed and the speed limit also decreases according to the degree of aggressiveness of the driver style. In other words, when the driver style is aggressive, the degree to which the actual vehicle speed approaches the speed limit is higher. It is worth noting that the correction factor cannot cause the actual vehicle speed to exceed the upper limit of the allowable deviation of the speed limit.

[0112] This represents the correction coefficient for calculating the PID coefficient and threshold based on the slope of the vehicle speed limit torque. When the current and future road slopes indicate a flat road, the correction coefficient for calculating the PID coefficient and threshold based on the slope is 1, meaning the default calibration is set according to flat road conditions. When the current and future road slopes indicate an uphill road, the correction coefficient for the PID coefficient of the vehicle speed limit torque calculation decreases as the slope increases, and the correction coefficient for the deviation threshold between the actual vehicle speed and the speed limit also decreases as the slope increases. In other words, the steeper the slope, the closer the actual vehicle speed is to the speed limit.

[0113] This represents the correction coefficient for calculating the PID coefficient and threshold based on the curvature of the speed limit torque. When the road is determined to be a straight road based on the curvature of the current and future roads, the correction coefficient for calculating the PID coefficient and threshold based on the slope is 1, meaning the default calibration is set according to the straight road type. When the road is determined to be a curved road based on the curvature of the current and future roads, the correction coefficient for the PID coefficient change in the speed limit torque calculation increases with the increase of curvature, and the correction coefficient for the deviation threshold between the actual vehicle speed and the speed limit also increases with the increase of curvature. In other words, the greater the curvature, the lower the allowable degree of actual vehicle speed approaching the speed limit.

[0114] The predictive cruise and speed limit coordinated control method provided by this invention takes the smaller of the acceleration / speed maintenance upper limit and the speed limit when calculating the coordinated upper and lower speed limits, reducing unnecessary acceleration / speed maintenance and improving the fuel-saving effect of predictive cruise. When calculating the coordinated upper and lower speed limits, the lower limit of the predictive cruise speed is dynamically calculated during low-speed cruise to avoid frequent cruise control retractions due to different vehicle models. When calculating the coordinated speed limit, the method considers the influence of driver style and road congestion, narrowing the allowable deviation threshold for the speed limit for aggressive drivers and when there is no congestion ahead and it is an uphill section, thus improving predictability. Cruise control improves fuel efficiency. When calculating predicted braking speed, the downhill braking speed threshold is calculated by referencing the map information and speed limit of the next uphill section to avoid exceeding the speed limit and causing engine speed fluctuations. When calculating cruise torque demand, cruise torque control adjusts the rate of change of torque demand based on the difference between the actual speed and the speed limit to avoid exceeding the speed limit and causing engine speed fluctuations. In free driving conditions, the speed limit torque is adjusted for PID parameters based on driver style, slope, and curvature, allowing for adaptive speed limit torque control for different driver styles and road slopes / curvatures, reducing calibration workload.

[0115] The above describes the steps of the predictive cruise and speed limit coordinated control method provided by this invention. As can be seen from the above description, according to the predictive cruise and speed limit coordinated control method provided by this invention, the upper and lower limits of the predictive cruise speed are adjusted based on road congestion level, road gradient information, and the current cruise speed to obtain corrected predictive cruise speed upper and lower limits. A predicted braking speed is calculated based on a comparison between the predicted speed sequence for coasting downhill in neutral and the coordinated speed limit value. Based on the corrected predictive cruise speed upper and lower limits and the predicted braking speed, the predictive cruise speed, predictive cruise gear, and predictive cruise gear control state are calculated. The predictive cruise gear and the predictive cruise gear control state are used to control the gear position during vehicle cruise. The cruise demand torque is adjusted based on a comparison between the actual speed and the speed limit, and the predicted cruise speed, to obtain a corrected cruise demand torque. Based on the predictive cruise mode and the corrected cruise demand torque, the calculation method for the speed limit demand torque is determined, and the speed limit demand torque is calculated according to the determined calculation method. Therefore, this invention achieves coordinated control of predictive cruise and speed limit, thereby improving the fuel-saving effect of predictive cruise.

[0116] The predictive cruise and speed limit coordinated control device provided by the present invention will be described below. The predictive cruise and speed limit coordinated control device described below can be referred to in correspondence with the predictive cruise and speed limit coordinated control method described above.

[0117] Figure 3 This is a schematic diagram of the predictive cruise and speed limit coordinated control device provided by the present invention, as shown below. Figure 3 As shown, the predictive cruise and speed limit coordinated control device provided by the present invention includes:

[0118] The first calculation module 301 is used to adjust the upper and lower limits of the predictive cruise speed based on the degree of road congestion, road slope information and the current cruise speed, to obtain the corrected upper and lower limits of the predictive cruise speed, and to calculate the predicted braking speed based on the comparison results of the predicted speed sequence of coasting downhill in neutral and the coordinated speed limit value.

[0119] The second calculation module 302 is used to calculate the predictive cruise speed, predictive cruise gear, and predictive cruise gear control state based on the corrected predictive cruise speed upper and lower limits and the predictive braking speed; wherein the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising.

[0120] The adjustment module 303 is used to adjust the cruise demand torque based on the comparison result between the actual vehicle speed and the limited vehicle speed and the predicted cruise speed, so as to obtain the corrected cruise demand torque.

[0121] The third calculation module 304 is used to determine the calculation method of the speed limit torque based on the predictive cruise mode and the corrected cruise demand torque, and to calculate the speed limit torque according to the determined calculation method.

[0122] The predictive cruise and speed limit coordinated control device provided by this invention adjusts the upper and lower limits of the predictive cruise speed based on road congestion level, road gradient information, and the current cruise speed to obtain corrected predictive cruise speed upper and lower limits. It also calculates the predicted braking speed based on a comparison between the predicted speed sequence during coasting downhill in neutral and the coordinated speed limit values. Based on the corrected predictive cruise speed upper and lower limits and the predicted braking speed, it calculates the predictive cruise speed, predictive cruise gear, and predictive cruise gear control state. The predictive cruise gear and the predictive cruise gear control state are used to control the gear position during vehicle cruise. Based on a comparison between the actual speed and the speed limit, and the predicted cruise speed, it adjusts the cruise torque demand to obtain a corrected cruise torque demand. Based on the predictive cruise mode and the corrected cruise torque demand, it determines the calculation method for the speed limit torque demand and calculates the torque demand according to the determined method. Therefore, this invention achieves coordinated control of predictive cruise and speed limit, improving the fuel-saving effect of predictive cruise.

[0123] Based on the above embodiments, in this embodiment, the first calculation module 301 is specifically used for:

[0124] The original speed limit is adjusted based on the degree of road congestion, road slope, and road curvature to obtain a coordinated speed limit.

[0125] The minimum value between the coordinated speed limit and the predictive cruise speed limit is used as the corrected predictive cruise speed limit.

[0126] Based on the above embodiments, in this embodiment, the first calculation module 301 is specifically used for:

[0127] The lower limit of the predictive cruise speed is adjusted based on the current cruise speed to obtain the corrected lower limit of the predictive cruise speed.

[0128] Where the current cruise speed is less than a preset speed threshold, the correction coefficient corresponding to the current cruise speed is negatively correlated with the current cruise speed.

[0129] Based on the above embodiments, in this embodiment, the first calculation module 301 is specifically used for:

[0130] If the next uphill is a short uphill with a slope length less than the preset slope length, and there is a first target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the coordinated vehicle speed limit, then when the vehicle is engaged in gear and braked at the first target position point, and the actual vehicle speed remains at the coordinated vehicle speed limit value, then coasting in gear is used for this downhill.

[0131] or,

[0132] If the next uphill slope is a long uphill slope with a gradient greater than or equal to the preset slope length, and there is a second target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the sum of the coordinated speed limit and the drift threshold, then engage gear and brake at the second target position point, and the actual vehicle speed is maintained at the coordinated speed limit plus the drift threshold.

[0133] Based on the above embodiments, in this embodiment, the adjustment module 303 is specifically used for:

[0134] The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the first demand torque. The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the intermediate demand torque. The intermediate demand torque is added to the cruise demand torque before correction to obtain the second demand torque.

[0135] The minimum value between the first required torque and the second required torque is determined as the corrected cruise required torque.

[0136] The cruise demand torque change rate correction coefficient is calculated based on the difference between the actual vehicle speed and the speed limit. If the difference is within the correction threshold range, the value of the cruise demand torque change rate correction coefficient is 1; otherwise, the cruise demand torque change rate correction coefficient is negatively correlated with the difference.

[0137] Based on the above embodiments, in this embodiment, the torque correction coefficient can be obtained by the following calculation method:

[0138] If the actual torque and the required torque change at the same rate, the torque correction factor is set to 1; otherwise, the quotient of the actual torque and the required torque is added to 1 and the result is used as the torque correction factor.

[0139] Based on the above embodiments, in this embodiment, the third calculation module 304 is specifically used for:

[0140] When the predictive cruise mode is map valid and the corrected cruise demand torque is positive, the corrected cruise demand torque is used as the vehicle speed limit demand torque.

[0141] or,

[0142] When the predictive cruise mode is in the case of an invalid map or when the vehicle is not in cruise mode, the required torque for the vehicle speed limit is calculated by PID control based on the actual vehicle speed and the speed limit.

[0143] Based on the above embodiments, in this embodiment, the third calculation module 304 is specifically used for:

[0144] The target correction coefficient is obtained by multiplying the first correction coefficient corresponding to the driving style, the second correction coefficient corresponding to the road slope, and the third correction coefficient corresponding to the road curvature.

[0145] The actual vehicle speed calculated by the PID control is corrected based on the target correction coefficient.

[0146] Wherein, the target correction coefficient is negatively correlated with the vehicle speed deviation value; the first correction coefficient is negatively correlated with the degree of aggressive driving; the second correction coefficient is positively correlated with the road slope value; the third correction coefficient is positively correlated with the road curvature; and the vehicle speed deviation value is the difference between the limited vehicle speed and the actual vehicle speed calculated by the PID control.

[0147] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device can be a robot or other electronic device, and may include: a processor 410, a communications interface 420, a memory 430, and a communication bus 440. The processor 410, communications interface 420, and memory 430 communicate with each other via the communication bus 440. The processor 410 can call logical instructions from the memory 430 to execute a predictive cruise and speed limit cooperative control method, including:

[0148] Based on the degree of road congestion, road gradient information, and the current cruise speed, the upper and lower limits of the predictive cruise speed are adjusted to obtain the corrected upper and lower limits of the predictive cruise speed. The predicted braking speed is calculated by comparing the predicted speed sequence based on coasting downhill in neutral with the coordinated speed limit.

[0149] Based on the corrected upper and lower limits of the predictive cruise speed and the predicted braking speed, the predictive cruise speed, the predictive cruise gear, and the predictive cruise gear control state are calculated; wherein, the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising.

[0150] Based on the comparison between the actual vehicle speed and the speed limit, and the predicted cruise speed, the cruise torque demand is adjusted to obtain the corrected cruise torque demand.

[0151] Based on the predictive cruise mode and the corrected cruise demand torque, the calculation method for the speed limit demand torque is determined, and the speed limit demand torque is calculated according to the determined calculation method.

[0152] Furthermore, the logical instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0153] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, wherein when the computer program is executed by a processor, the computer is able to execute the predictive cruise and speed limit cooperative control method provided by the above methods, including:

[0154] Based on the degree of road congestion, road gradient information, and the current cruise speed, the upper and lower limits of the predictive cruise speed are adjusted to obtain the corrected upper and lower limits of the predictive cruise speed. The predicted braking speed is calculated by comparing the predicted speed sequence based on coasting downhill in neutral with the coordinated speed limit.

[0155] Based on the corrected upper and lower limits of the predictive cruise speed and the predicted braking speed, the predictive cruise speed, the predictive cruise gear, and the predictive cruise gear control state are calculated; wherein, the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising.

[0156] Based on the comparison between the actual vehicle speed and the speed limit, and the predicted cruise speed, the cruise torque demand is adjusted to obtain the corrected cruise torque demand.

[0157] Based on the predictive cruise mode and the corrected cruise demand torque, the calculation method for the speed limit demand torque is determined, and the speed limit demand torque is calculated according to the determined calculation method.

[0158] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the predictive cruise and speed limit cooperative control method provided by the above methods, including:

[0159] Based on the degree of road congestion, road gradient information, and the current cruise speed, the upper and lower limits of the predictive cruise speed are adjusted to obtain the corrected upper and lower limits of the predictive cruise speed. The predicted braking speed is calculated by comparing the predicted speed sequence based on coasting downhill in neutral with the coordinated speed limit.

[0160] Based on the corrected upper and lower limits of the predictive cruise speed and the predicted braking speed, the predictive cruise speed, the predictive cruise gear, and the predictive cruise gear control state are calculated; wherein, the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising.

[0161] Based on the comparison between the actual vehicle speed and the speed limit, and the predicted cruise speed, the cruise torque demand is adjusted to obtain the corrected cruise torque demand.

[0162] Based on the predictive cruise mode and the corrected cruise demand torque, the calculation method for the speed limit demand torque is determined, and the speed limit demand torque is calculated according to the determined calculation method.

[0163] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0164] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A predictive cruise and speed limit coordinated control method, characterized in that, include: Based on the degree of road congestion, road gradient information, and the current cruise speed, the upper and lower limits of the predictive cruise speed are adjusted to obtain the corrected upper and lower limits of the predictive cruise speed. The predicted braking speed is calculated by comparing the predicted speed sequence based on coasting downhill in neutral with the coordinated speed limit. Based on the corrected upper and lower limits of the predictive cruise speed and the predicted braking speed, the predictive cruise speed, the predictive cruise gear, and the predictive cruise gear control state are calculated; wherein, the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising. Based on the comparison between the actual vehicle speed and the speed limit, and the predicted cruise speed, the cruise torque demand is adjusted to obtain the corrected cruise torque demand. Based on the predictive cruise mode and the corrected cruise demand torque, the calculation method for the speed limit demand torque is determined, and the speed limit demand torque is calculated according to the determined calculation method. The method of adjusting the cruise demand torque based on the comparison between the actual vehicle speed and the speed limit, and the predicted cruise speed, to obtain the corrected cruise demand torque includes: The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the first demand torque. The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the intermediate demand torque. The intermediate demand torque is added to the cruise demand torque before correction to obtain the second demand torque. The minimum value between the first required torque and the second required torque is determined as the corrected cruise required torque. The cruise demand torque change rate correction coefficient is calculated based on the difference between the actual vehicle speed and the speed limit. If the difference is within the correction threshold range, the value of the cruise demand torque change rate correction coefficient is 1; otherwise, the cruise demand torque change rate correction coefficient is negatively correlated with the difference. The torque correction coefficient is obtained through the following calculation method: If the actual torque and the required torque change at the same rate, the torque correction factor is set to 1; otherwise, the quotient of the actual torque and the required torque is added to 1 and the result is used as the torque correction factor.

2. The predictive cruise and speed limit coordinated control method according to claim 1, characterized in that, The process of adjusting the predictive cruise speed upper and lower limits based on road congestion level, road gradient information, and the current cruise speed to obtain the corrected predictive cruise speed upper and lower limits includes: The original speed limit is adjusted based on the degree of road congestion, road slope, and road curvature to obtain a coordinated speed limit. The minimum value between the coordinated speed limit and the predictive cruise speed limit is used as the corrected predictive cruise speed limit.

3. The predictive cruise and speed limit coordinated control method according to claim 1, characterized in that, The process of adjusting the predictive cruise speed upper and lower limits based on road congestion level, road gradient information, and the current cruise speed to obtain the corrected predictive cruise speed upper and lower limits includes: The lower limit of the predictive cruise speed is adjusted based on the current cruise speed to obtain the corrected lower limit of the predictive cruise speed. Where the current cruise speed is less than a preset speed threshold, the correction coefficient corresponding to the current cruise speed is negatively correlated with the current cruise speed.

4. The predictive cruise and speed limit coordinated control method according to claim 1, characterized in that, The calculation of the predicted braking speed based on the comparison results between the predicted vehicle speed sequence for coasting downhill in neutral and the coordinated vehicle speed limit includes: If the next uphill is a short uphill with a slope length less than the preset slope length, and there is a first target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the coordinated vehicle speed limit, then when the vehicle is engaged in gear and braked at the first target position point, and the actual vehicle speed remains at the coordinated vehicle speed limit value, then coasting in gear is adopted for this downhill. or, If the next uphill slope is a long uphill slope with a gradient greater than or equal to the preset slope length, and there is a second target position point in the predicted vehicle speed sequence for coasting downhill in neutral that is greater than the sum of the coordinated speed limit and the drift threshold, then engage the gear and brake at the second target position point, and the actual vehicle speed is maintained at the coordinated speed limit plus the drift threshold.

5. The predictive cruise and speed limit coordinated control method according to claim 1, characterized in that, The method for determining the speed limit torque requirement based on the predictive cruise mode and the corrected cruise torque requirement, and calculating the speed limit torque requirement according to the determined method, includes: When the predictive cruise mode is map valid and the corrected cruise demand torque is positive, the corrected cruise demand torque is used as the vehicle speed limit demand torque. or, When the predictive cruise mode is in the case of an invalid map or when the vehicle is not in cruise mode, the required torque for the vehicle speed limit is calculated by PID control based on the actual vehicle speed and the speed limit.

6. The predictive cruise and speed limit coordinated control method according to claim 5, characterized in that, The calculation of the required torque for the vehicle speed limit based on the actual vehicle speed and the vehicle speed limit using PID control includes: The target correction coefficient is obtained by multiplying the first correction coefficient corresponding to the driving style, the second correction coefficient corresponding to the road slope, and the third correction coefficient corresponding to the road curvature. The actual vehicle speed calculated by the PID control is corrected based on the target correction coefficient. Wherein, the target correction coefficient is negatively correlated with the vehicle speed deviation value; the first correction coefficient is negatively correlated with the degree of aggressive driving; the second correction coefficient is positively correlated with the road slope value; the third correction coefficient is positively correlated with the road curvature; and the vehicle speed deviation value is the difference between the limited vehicle speed and the actual vehicle speed calculated by the PID control.

7. A predictive cruise and speed limit coordinated control device, characterized in that, include: The first calculation module is used to adjust the upper and lower limits of the predictive cruise speed based on the degree of road congestion, road slope information and the current cruise speed, to obtain the corrected upper and lower limits of the predictive cruise speed, and to calculate the predicted braking speed based on the comparison results of the predicted speed sequence of coasting downhill in neutral and the coordinated speed limit value. The second calculation module is used to calculate the predictive cruise speed, predictive cruise gear, and predictive cruise gear control state based on the corrected predictive cruise speed upper and lower limits and the predictive braking speed; wherein the predictive cruise gear and the predictive cruise gear control state are used to control the gear when the vehicle is cruising. The adjustment module is used to adjust the cruise demand torque based on the comparison result between the actual vehicle speed and the limited vehicle speed and the predicted cruise speed, so as to obtain the corrected cruise demand torque. The third calculation module is used to determine the calculation method of the speed limit torque based on the predictive cruise mode and the corrected cruise demand torque, and to calculate the speed limit torque according to the determined calculation method. The adjustment module is specifically used for: The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the first demand torque. The cruise demand torque before correction is adjusted based on the cruise demand torque change rate correction coefficient and the torque correction coefficient to obtain the intermediate demand torque. The intermediate demand torque is added to the cruise demand torque before correction to obtain the second demand torque. The minimum value between the first required torque and the second required torque is determined as the corrected cruise required torque. The cruise demand torque change rate correction coefficient is calculated based on the difference between the actual vehicle speed and the speed limit. If the difference is within the correction threshold range, the value of the cruise demand torque change rate correction coefficient is 1; otherwise, the cruise demand torque change rate correction coefficient is negatively correlated with the difference. The torque correction coefficient is obtained through the following calculation method: If the actual torque and the required torque change at the same rate, the torque correction factor is set to 1; otherwise, the quotient of the actual torque and the required torque is added to 1 and the result is used as the torque correction factor.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the predictive cruise and speed limit cooperative control method as described in any one of claims 1 to 6.

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