Method and apparatus for regulating speed of autonomous vehicle
By receiving information about the target vehicle and replacing the set acceleration with the target acceleration when the alarm signal is activated, the problem of autonomous vehicles suddenly approaching the target vehicle is solved, improving responsiveness and passenger comfort.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- PEUGEOT CITROEN AUTOMOBILES SA
- Filing Date
- 2021-11-04
- Publication Date
- 2026-06-23
AI Technical Summary
When the autonomous vehicle slows down, the delayed response causes the distance between the vehicles to be disregarded, resulting in the vehicle suddenly approaching the target vehicle and affecting the psychological comfort of the occupants.
By receiving distance, speed, and acceleration information of the target vehicle, the system calculates the time between the vehicles and replaces the set acceleration with the target acceleration when the alarm signal is activated, thereby adjusting the speed of the autonomous vehicle to avoid sudden approach.
It improves the responsiveness of autonomous vehicles and the comfort of passengers, reduces the need for emergency braking, and ensures reasonable control of the distance between vehicles.
Smart Images
Figure CN116601067B_ABST
Abstract
Description
Technical Field
[0001] This invention claims priority to French application No. 2013450, filed on December 17, 2020, the contents of which (text, drawings, and claims) are incorporated herein by reference. This invention relates to the field of driver assistance systems for autonomous vehicles. Specifically, this invention relates to the regulation of the speed of an autonomous vehicle by an adaptive speed regulator. Background Technology
[0002] Vehicle "acceleration" is understood as the change in vehicle speed per unit time. This acceleration can be positive or negative. Deceleration is negative acceleration. "Vehicle" is understood as any type of vehicle, such as motor vehicles, motorized bicycles, motorcycles, storage robots in warehouses, etc. "Autonomous driving" of "autonomous vehicles" is understood as any method that can assist the driving of said vehicle. The method may thus include partially or completely guiding said vehicle or providing any type of assistance to the natural person driving said vehicle. The method thus covers autonomous driving from Level 0 to Level 5 in the OICA (Organisation International des Constructeurs Automobiles) rating system.
[0003] Adaptive Cruise Control (ACC) is a known ADAS system used to regulate vehicle speed and inter-vehicle time, which represents the duration for two vehicles traveling in the same lane to pass each other in front or behind. This inter-vehicle time is, for example, a pre-determined parameter by the driver or a pre-determined parameter defaulted to according to current regulatory recommendations (e.g., 2 seconds). A simple relationship is established between inter-vehicle time and inter-vehicle distance through vehicle speed. ACC for autonomous vehicles typically includes radar or lidar capable of detecting a vehicle ahead, referred to as the target vehicle, and measuring the inter-vehicle distance between the autonomous vehicle and the target vehicle. The speed and acceleration of the target vehicle are also measured or determined. The ACC can thus determine the inter-vehicle time based on the inter-vehicle distance and the speed of the autonomous vehicle. However, when the target vehicle decelerates to a stop with strong deceleration (negative acceleration), the distance between the vehicles is not maintained due to delays (attributable to the time required for receiving the measured data, the calculation time for the setpoint, and the actuator (approximately 500 ms)). This is particularly noticeable when the speed is low (less than 50 km / h). The autonomous vehicle thus approaches the target vehicle too suddenly, causing psychological discomfort to the vehicle's occupants and occasionally triggering emergency braking. Summary of the Invention
[0004] The objective of this invention is to correct the aforementioned problems, particularly to improve responsiveness and enhance the psychological comfort of the occupants of the autonomous vehicle.
[0005] Therefore, a first aspect of the present invention relates to a method for adjusting the adaptive speed of an autonomous vehicle, referred to as an ego vehicle, the method comprising the following steps:
[0006] ● Activate the adaptive speed regulator, which is based on a set acceleration calculated based on a predetermined inter-vehicle time, which defines the distance between the autonomous vehicle and a target vehicle in front of the autonomous vehicle.
[0007] ● Receive information related to the target vehicle, referred to as target information, which represents the distance of the target vehicle relative to the self-vehicle, referred to as target distance, and the acceleration of the target vehicle, referred to as target acceleration;
[0008] ● Receive information related to the self-vehicle, referred to as self-vehicle information, which represents the speed of the self-vehicle, referred to as self-speed;
[0009] ● Determine the inter-vehicle time calculated based on the target information and the self-vehicle information;
[0010] ● An alarm signal is determined based on the target information and the self-vehicle information. When the calculated time between vehicles is less than a predetermined percentage of the predetermined set time between vehicles, the alarm signal is activated.
[0011] ●When the alarm signal is in the active state and when the target acceleration is less than the calculated set acceleration, the method further includes a replacement step for replacing the set acceleration of the speed regulator with the target acceleration.
[0012] Therefore, when the time between vehicles is less than a predetermined percentage of the time between vehicles and when the target acceleration is less than a calculated set acceleration, the autonomous vehicle begins to approach the target vehicle too suddenly. The speed regulator adjusts the speed of the autonomous vehicle according to the acceleration of the target vehicle, and thus causes the autonomous vehicle to decelerate more sharply than when the speed regulator adjusts the speed of the autonomous vehicle according to the calculated set acceleration. The autonomous vehicle thus approaches the target vehicle less suddenly, and the distance between the autonomous vehicle and the target vehicle is greater. Emergency braking is no longer required. The occupants of the autonomous vehicle feel a greater deceleration from the first moment and are thus reassured due to the good consideration for the target vehicle. The autonomous vehicle is thus more responsive.
[0013] Advantageously, the alarm signal is activated when the target acceleration is less than a predetermined maximum deceleration threshold.
[0014] Therefore, the calculated set acceleration is replaced by the target acceleration only when the target deceleration is large and when strong responsiveness is required.
[0015] Advantageously, the alarm signal is activated when the self-velocity is less than a predetermined self-velocity threshold.
[0016] This ensures that when the self-speed is high (e.g., greater than 50 km / h) and the speed adjustment is not very sensitive to delays (which are attributed to the reception of measured data, the calculation time for calculating the set value, and the actuator), there is no replacement of the calculated set acceleration with the target acceleration.
[0017] Advantageously, the target information also characterizes the speed of the target vehicle, referred to as the target speed, and the alarm signal is activated when the target speed is less than the self-speed.
[0018] This ensures that when the speed of the target vehicle is greater than the self-speed and therefore when the distance between the vehicles increases, there is no replacement of the calculated set acceleration by the target acceleration.
[0019] Advantageously, the predetermined percentage is a value between 60% and 120%;
[0020] Therefore, the higher the predetermined percentage value, the more predictable the speed adjustment, which classifies the road behavior of the autonomous vehicle.
[0021] Advantageously, the alarm signal is transmitted via at least one wireless communication channel to at least one infrastructure, at least one vehicle, and / or at least one device capable of receiving information transmitted via the wireless communication channel.
[0022] When a severe deceleration is detected, the autonomous vehicle may communicate the detected situation to other vehicles to inform them so that the other vehicles can adapt their behavior to the situation (e.g., deceleration).
[0023] A second aspect of the invention relates to an apparatus comprising a memory associated with at least one processor configured to implement a method according to a first aspect of the invention.
[0024] The present invention also relates to a vehicle that includes the device.
[0025] The present invention also relates to a computer program comprising instructions adapted to perform the steps of the method according to the first aspect of the present invention when the program is executed by at least one processor. Attached Figure Description
[0026] Other features and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments and the accompanying drawings, in which:
[0027] - Figure 1 An apparatus according to a specific embodiment of the present invention is illustrated schematically.
[0028] - Figure 2 A method for adjusting the speed of an autonomous vehicle according to a specific embodiment of the present invention is illustrated schematically. Detailed Implementation
[0029] In the following description, the invention is used in a non-limiting application in the case of an autonomous motor vehicle traveling on a road or in a traffic lane. Other applications (e.g., robots in storage warehouses or motorcycles on rural roads) are also possible.
[0030] Figure 1 An example of a device 101 included in a vehicle, a network (“cloud”), or a server is shown. This device 101 can be used as a centralized device responsible for the functions referred to below. Figure 2 The described method includes at least some steps. In an embodiment, the device corresponds to an autonomous driving computer.
[0031] In this invention, device 101 is included in the vehicle.
[0032] The device 101 can take the form of a box including printed circuits, any type of computer, or a mobile phone (“smartphone”).
[0033] The apparatus 101 includes a random access memory 102 for storing instructions for a processor 103 to perform at least one step of the method described above. The apparatus also includes a mass storage memory 104 for storing data to be retained after the method has been performed.
[0034] The device 101 may also include a digital signal processor (DSP) 105. The DSP 105 receives data and shapes, demodulates, and amplifies the data in a manner known to it.
[0035] The device 101 further includes an input interface 106 and an output interface 107, the input interface being used to receive data implemented by the method according to the invention, and the output interface being used to transmit data implemented by the method according to the invention.
[0036] Figure 2 A method for adjusting the speed of an autonomous vehicle according to a specific embodiment of the present invention is illustrated schematically.
[0037] Step 201 (“Activ”) is an activation step for activating an adaptive speed regulator that is based on a set acceleration calculated based on a predetermined set inter-vehicle time, which defines the distance between the ego vehicle and a target vehicle ahead of the ego vehicle.
[0038] Generally, the adaptive speed regulator calculates and sets the required acceleration for the autonomous vehicle at each moment, ensuring that the autonomous vehicle maintains a predetermined speed and a predetermined inter-vehicle time. This acceleration is applied by a power propulsion component (engine, brakes, etc.). The predetermined speed and inter-vehicle time are, for example, input by the occupants or driver of the autonomous vehicle. The speed regulation modifies the autonomous vehicle's speed to maintain the predetermined inter-vehicle time.
[0039] Step 202 (“ReceiptCble”) is a receiving step for receiving information related to the target vehicle, referred to as target information, which represents the distance of the target vehicle relative to the ego vehicle, referred to as target distance, and the acceleration of the target vehicle, referred to as target acceleration. In the operating mode, the target information also represents the speed of the target vehicle, referred to as target speed.
[0040] The target distance, target velocity, and target acceleration are information obtained periodically by processing measurements from onboard sensors present in a vehicle with a conventional adaptive speed regulator. In operating mode, the input interface 106 of the apparatus for implementing the invention receives this information.
[0041] Step 203 (“RecepEgo”) is a receiving step for receiving information related to the self-vehicle, referred to as self-vehicle information, which represents the speed of the self-vehicle, referred to as self-speed.
[0042] The self-velocity is information obtained periodically by processing measurements from onboard sensors present in vehicles with conventional adaptive speed regulators. In operating mode, the input interface 106 of the apparatus for implementing the invention receives this information.
[0043] Step 204 (“DetTiV”) is a determination step for determining the inter-vehicle time calculated based on the target information and the ego vehicle information. The inter-vehicle time is periodically obtained by multiplying the inter-vehicle distance by the ego speed. This inter-vehicle time is calculated periodically, for example, by device 101.
[0044] Step 205 (“DetSgnl”) is a determination step used to determine an alarm signal based on the target information and the self-vehicle information. The alarm signal is activated when the calculated inter-vehicle time is less than a predetermined percentage of a predetermined set inter-vehicle time. The predetermined percentage is a value between 60% and 120%, for example, 80%. Other values are also possible.
[0045] Advantageously, the alarm signal is activated for a combination of the following conditions:
[0046] ●The calculated time between vehicles is less than a predetermined percentage of the predetermined set time between vehicles.
[0047] ● The target acceleration is less than a predetermined maximum deceleration threshold. For example, the predetermined maximum deceleration threshold is -3 m / s². Other values are also possible.
[0048] ● The self-velocity is less than a predetermined self-velocity threshold. For example, the predetermined self-velocity threshold is 50 km / h or 30 mkm / h; other values are also possible.
[0049] ●When the target speed is less than the self-speed.
[0050] Step 206 (“Test”) is a verification step used to verify whether the alarm signal is in the active state and whether the target acceleration is less than the calculated set acceleration. In the affirmative, the voluntary vehicle approaches the target vehicle too suddenly, the vehicle distance is not maintained, and the target vehicle decelerates more than the voluntary vehicle. The calculated set acceleration needs to be modified very quickly by a conventional vehicle speed regulator.
[0051] Step 207 (“Regul”) is a replacement step, which replaces the set acceleration of the speed regulator with the target acceleration. The set acceleration calculated by a conventional vehicle speed regulator is insufficient.
[0052] The calculated set acceleration is therefore replaced by a weaker target acceleration. The speed regulator thus treats the target acceleration as the set acceleration. This allows the vehicle to decelerate more quickly, resulting in the aforementioned advantages.
[0053] Advantageously, the alarm signal is transmitted via at least one wireless communication channel to at least one infrastructure, at least one vehicle, and / or at least one device capable of receiving information transmitted via the wireless communication channel to notify the declaration. For example, another autonomous vehicle receiving the alarm signal and following the autonomous vehicle can anticipate slowing down and therefore decelerate.
[0054] This invention is not limited to the embodiments described above as examples; the invention extends to other variations.
[0055] For example, wireless communication was also described above. The new wireless long-range communication standard includes specifications specifically for motor vehicle applications. Therefore, a short-range wireless communication channel for vehicle-to-everything (V2X) has been designated.
[0056] The first type of V2X channel is based on the Wi-Fi standard (IEEE 802.11p) and is responsible for communication between vehicles and between vehicles and infrastructure.
[0057] The second type of V2X channel is built on cellular standards, and especially on 5G standards. This second type of V2X channel is responsible for communication between vehicles, between vehicles and infrastructure, or between vehicles and cellular networks. This type of channel coexists with traditional cellular channels and is specifically referred to as "sidelink" or "PC5".
[0058] V2X communication can also be implemented by user equipment.
Claims
1. A method for regulating the speed of an autonomous vehicle, referred to as a self-vehicle, the self-vehicle including an adaptive speed regulator, the method comprising the steps of: ● Activate (201) the adaptive speed regulator, which is based on a set acceleration calculated based on a predetermined set time between vehicles, which defines the distance between the autonomous vehicle and a target vehicle in front of the autonomous vehicle. ● Receive (202) information relating to the target vehicle, referred to as target information, the target information representing the distance of the target vehicle relative to the self-vehicle, referred to as target distance, and the acceleration of the target vehicle, referred to as target acceleration; ● Receive (203) information relating to the self-vehicle, referred to as self-vehicle information, which represents the speed of the self-vehicle, referred to as self-vehicle speed; ● Determine (204) the inter-vehicle time calculated based on the target information and the self-vehicle information; ● Based on the target information and the self-vehicle information, an alarm signal (205) is determined. When the calculated inter-vehicle time is less than a predetermined percentage of the predetermined set inter-vehicle time, the alarm signal is in an active state. ● When the alarm signal (206) is in the active state and when the target acceleration is less than the calculated set acceleration, the method further includes a replacement step for replacing the set acceleration of the adaptive speed regulator (207) with the target acceleration.
2. The method according to claim 1, wherein, The alarm signal is in the active state when the target acceleration is less than a predetermined maximum deceleration threshold.
3. The method according to claim 1 or 2, wherein, The alarm signal is in the active state when the self-velocity is less than a predetermined self-velocity threshold.
4. The method according to claim 1 or 2, wherein, The target information also represents the speed of the target vehicle, referred to as the target speed, and the alarm signal is in the active state when the target speed is less than the self-speed.
5. The method according to claim 1 or 2, wherein, The predetermined percentage is a value between 60% and 120%.
6. The method according to claim 1 or 2, wherein, The alarm signal is transmitted via at least one wireless communication channel to at least one infrastructure, at least one vehicle, and / or at least one device capable of receiving information transmitted via the wireless communication channel.
7. An apparatus (101) including a memory (102) associated with at least one processor (103), said at least one processor being configured to implement the method according to any one of the preceding claims.
8. A vehicle comprising the device according to claim 7.
9. A computer program product comprising a computer program, the computer program including instructions adapted to perform the steps of the method according to any one of claims 1 to 6 when the computer program is executed by at least one processor (103).