Vehicle Systems

Abstract

The present invention relates to a vehicle system that makes it difficult for vehicle control to be suspended due to operational limitations of an onboard device mounted on the vehicle. In this vehicle system, the target driving state during vehicle control is changed based on the operational limitations of the onboard device. For example, while operating the onboard device to achieve the target driving state, the target driving state can be changed if it is predicted that the onboard device has reached a state where protection control should be initiated. As a result, the initiation of protection control can be made difficult, making it difficult for vehicle control to be suspended.

Description

Technical Field

[0001] The present invention relates to vehicle systems. Background Art

[0002] Patent Document 1 describes a vehicle system that performs automated driving. In the vehicle system described in Patent Document 1, the vehicle's stopping position is determined based on road conditions detected by an external recognition device, such as a camera. The vehicle's driving plan (driving path, deceleration, and stopping position) is then modified based on the roadside condition at the determined stopping position.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-163984 Summary of the Invention

[0004] An object of the present invention is to make it difficult for vehicle control to be suspended due to operational restrictions of an onboard device mounted on the vehicle.

[0005] For example, in order to prevent overheating of onboard devices, vehicle systems are typically designed to implement protective control that restricts the operation of the onboard devices. However, if protective control is initiated on an onboard device, vehicle control may be suspended. To address this issue, the present vehicle system changes the target driving state during vehicle control based on the operational restrictions of the onboard devices. For example, while operating an onboard device to achieve the target driving state, the target driving state can be changed if it is predicted that the onboard device will reach a state where protective control is initiated. This makes it difficult to initiate protective control and thus difficult to terminate vehicle control.

[0006] (1) A vehicle system comprising:

[0007] an on-vehicle device, which is installed in a vehicle; and

[0008] a control device for controlling the vehicle-mounted device so that the vehicle travels in a target driving state;

[0009] in,

[0010] The above-mentioned control device includes:

[0011] a prediction unit that predicts a state of the vehicle-mounted device when the vehicle is traveling in the target driving state; and

[0012] The correction unit corrects the target driving state when it is determined that the operation of the onboard device needs to be restricted based on the state of the onboard device predicted by the prediction unit.

[0013] The target driving state can be represented by the vehicle's target driving values ​​(e.g., target driving speed, target longitudinal acceleration, target lateral acceleration, etc.) as indicated by the driving plan in autonomous driving, or by target driving values ​​(e.g., target inter-vehicle distance, target steering state, etc.) in driving assistance. The target driving state also includes the planned driving path in autonomous driving. This is because the vehicle's driving state changes according to the planned driving path and the operating status of onboard devices changes.

[0014] (2) The vehicle system according to item (1), wherein:

[0015] The control device includes a travel plan creating unit that creates a travel plan for the vehicle, and controls the on-vehicle device so that the vehicle travels according to the travel plan created by the travel plan creating unit.

[0016] A driving plan includes candidate driving routes (also referred to as planned driving routes), target driving values ​​(such as target driving speed, target lateral acceleration, and target longitudinal acceleration set for each of the planned driving routes, if the planned driving route includes one or more segments). Furthermore, the driving plan creation unit can function as a correction unit for correcting the driving plan. The correction unit corrects at least one of the candidate driving routes and the target driving values ​​in the driving plan.

[0017] (3) A vehicle system according to item (1) or (2), wherein:

[0018] The control device includes a determination unit configured to determine that the operation of the onboard device needs to be restricted when the state of the onboard device predicted by the prediction unit exceeds a predetermined set state.

[0019] (4) The vehicle system according to item (3), wherein:

[0020] The prediction unit predicts a temperature as a state of the vehicle-mounted device.

[0021] The determination unit determines that it is necessary to restrict the operation of the in-vehicle device when the predicted temperature of the in-vehicle device exceeds a set temperature serving as the set state.

[0022] (5) The vehicle system according to any one of items (1) to (4), wherein:

[0023] The above-mentioned control device includes:

[0024] a driving plan creating unit that creates a driving plan for the vehicle; and

[0025] The notification unit requests the driving plan creation unit to reset the driving plan and notifies the upper limit value of at least one target driving value representing the target driving state when it is determined that the operation of the vehicle-mounted device needs to be restricted based on the state of the vehicle-mounted device predicted by the prediction unit.

[0026] The upper limit of the target running value can be determined so that the predicted state of the vehicle-mounted device is determined as not requiring a restricted operation. The upper limit of the target running value can be, for example, an upper limit of a target lateral acceleration serving as the target running value or an upper limit of an average value of the target lateral acceleration.

[0027] (6) The vehicle system according to any one of items (1) to (5), wherein:

[0028] The vehicle-mounted device includes a steering actuator for steering a steering wheel of the vehicle.

[0029] The target driving state includes the target turning state of the vehicle.

[0030] The control device includes a steering actuator control unit that controls the steering actuator so that the vehicle travels in the target turning state.

[0031] The correction unit corrects the target turning state when it is determined that the operation of the steering actuator needs to be restricted.

[0032] The target turning state can be represented by a target lateral acceleration, a target lateral jerk, etc. The correction unit can reduce the maximum value of at least one of the target lateral acceleration and the target lateral jerk, or reduce the average value of at least one of the target lateral acceleration and the target lateral jerk.

[0033] (7) The vehicle system according to item (6), wherein:

[0034] The steering actuator control unit obtains a target operating state of the steering actuator for the vehicle to travel in the target turning state, and controls the steering actuator so that the actual operating state of the steering actuator approaches the target operating state.

[0035] The prediction unit predicts a temperature of the steering actuator when the steering actuator is operated in the target operation state.

[0036] For example, when the steering actuator is a steering motor, the target operating state can be expressed by a target rotational speed, a target torque, and the like of the steering motor.

[0037] (8) The vehicle system according to item (6) or (7), wherein:

[0038] The control device includes a travel plan creating unit for creating a travel plan for the vehicle.

[0039] The target driving state is the driving plan including the planned driving path and the target turning state of the vehicle.

[0040] The steering actuator control unit controls the steering actuator so that the vehicle travels according to the travel plan.

[0041] The prediction unit predicts the temperature as the state of the steering actuator based on a current temperature of the steering actuator and an amount of heat generated and dissipated by the steering actuator while the vehicle travels along the planned travel route according to the target turning state.

[0042] (9) A vehicle system comprising:

[0043] an on-vehicle device, which is installed in a vehicle; and

[0044] a control device for controlling the vehicle-mounted device so that the vehicle travels according to the travel plan;

[0045] in,

[0046] The above-mentioned control device includes:

[0047] a prediction unit that predicts a state of the vehicle-mounted device when the vehicle travels according to the travel plan; and

[0048] The correction unit corrects the travel plan when determining that the operation of the onboard device needs to be restricted based on the state of the onboard device predicted by the prediction unit.

[0049] The vehicle system described in this item can adopt the technical features described in any one of items (1) to (8).

[0050] (10) A vehicle system comprising:

[0051] Steering actuators, which steer the vehicle's wheels; and

[0052] a steering actuator control device for controlling the steering actuator so that the vehicle travels according to the travel plan;

[0053] in,

[0054] The above driving plan includes the planned driving route and the target turning state.

[0055] The steering actuator control device comprises:

[0056] a prediction unit that predicts a temperature of the steering actuator when the steering actuator is controlled so that the vehicle travels along the planned travel route in the target turning state; and

[0057] The correction unit corrects at least one of the target turning state and the planned travel route when the temperature of the steering actuator predicted by the prediction unit is higher than a set temperature.

[0058] The vehicle system described in this item can adopt the technical features described in any one of items (1) to (9). BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a diagram schematically showing a vehicle system according to the present embodiment.

[0060] Figure 2 This is a flowchart showing a driving plan permission / disapproval routine stored in the control device of the vehicle system.

[0061] Figure 3 This is a flowchart showing a driving plan correction program stored in the control device.

[0062] Figure 4 This is a flowchart showing the automatic driving program stored in the above-mentioned control device.

[0063] Figure 5 This is a flowchart showing an actuator control program stored in the above-mentioned control device.

[0064] Figure 6 A diagram schematically showing a travel plan. DETAILED DESCRIPTION

[0065] Hereinafter, a vehicle system according to an embodiment of the present invention will be described with reference to the drawings.

[0066] like Figure 1 As shown, the vehicle system includes a control device 10 , a driving motor 12 as a plurality of vehicle-mounted devices, a driving battery 14 , a braking actuator 16 , and a steering motor 18 as a steering actuator.

[0067] The control device 10 includes an automatic driving controller 20, a drive ECU (Electronic Control Unit) 22, a battery ECU 24, a brake ECU 26, a steering ECU 28, and the like. Each of these components, including the automatic driving controller 20, the drive ECU 22, the battery ECU 24, the brake ECU 26, and the steering ECU 28, utilizes a computer as its primary component, and information is communicated between them. Furthermore, a peripheral information acquisition device 30 and a sensor group 32 are connected to the control device 10.

[0068] The surrounding information acquisition device 30 includes a camera, radar, and the like. Based on the information from these devices, it identifies objects and the like surrounding the vehicle, determines the relative position between the vehicle and the objects, and determines the road conditions. The road conditions include the curvature and slope of the road.

[0069] The sensor group 32 includes a plurality of sensors. These sensors include, for example, a vehicle speed sensor for detecting the vehicle's running speed, a voltage sensor for detecting the voltage of the drive battery 14, a rotational speed sensor for detecting the rotational speed of the steering motor 18, a steering angle sensor for detecting the steering angle of the vehicle's steering wheel, a motor temperature sensor 32a for detecting the temperature of the steering motor 18, and an outside air temperature sensor 32b for detecting the outside air temperature.

[0070] The automatic driving controller 20 includes a driving plan creating section 40 and a control instruction value creating section 42 .

[0071] The driving plan creating unit 40 creates a driving plan based on navigation information including map information, or modifies a created driving plan. Figure 6 A driving plan is schematically shown in FIG. The driving plan includes candidate driving routes (also referred to as planned driving routes) and target driving values. Known route search methods can be used to explore and create candidate driving routes to the destination, i.e., driving route candidates. Target driving values ​​include target driving speed, target lateral acceleration, target lateral jerk, target longitudinal acceleration, and other parameters for each of the multiple sections included in the driving route candidate. Furthermore, when creating the driving plan, information such as the road conditions obtained by the surrounding information acquisition device 30 and the relative positional relationship between the vehicle and objects are also considered.

[0072] Furthermore, changes in driving route candidates, changes in target driving values ​​(one or more of target driving speed, target lateral acceleration, target lateral jerk, target longitudinal acceleration, etc.), etc., are equivalent to revisions of the driving plan.

[0073] The control command value generator 42 generates control command values ​​for the drive motor 12, brake actuator 16, steering motor 18, and the like, for driving the vehicle according to the driving plan generated by the driving plan generator 40. The control command values ​​generated by the control command value generator 42 are supplied to the drive ECU 22, brake ECU 26, steering ECU 28, and the like. Furthermore, the control command value generator 42 generates control command values ​​for the cooling fan included in the drive battery 14 and supplies them to the battery ECU 24.

[0074] The drive ECU 22 controls the drive motor 12 and other components based on control command values, while the battery ECU 24 controls the cooling fan based on control command values. In electric vehicles, the drive motor 12 is the driving source. In hybrid vehicles, the driving source includes the drive motor 12 and the engine. Control of the drive motor 12 controls the vehicle's speed, longitudinal acceleration, and other parameters.

[0075] The brake ECU 26 controls the brake actuator 16 and other components based on control command values. The brake actuator 16 includes components such as the electric motor that drives the electric brake and the solenoid valve that controls the hydraulic pressure of the hydraulic brake. Control of the brake actuator 16 controls the vehicle's deceleration and, consequently, its travel speed.

[0076] The steering ECU 28 controls the steering motor 18 and the like based on a control command value.

[0077] The steering motor 18 can be a motor that twists the steering shaft (also known as a power steering motor) in a steering system where the torsion of the steering shaft is converted into lateral movement of the steering tie rods via a gear rack to steer the wheels. Alternatively, it can be a motor independently provided for each steerable wheel in a steering system where the steerable wheels are independently steered. Control of the steering motor 18 controls the vehicle's turning state, for example.

[0078] Executed every cycle time Figure 5 The actuator control program is shown in the flowchart.

[0079] In step 51 (hereinafter, simply referred to as S51 ; the same applies to other steps), a control command value is acquired, and in S52 , the steering motor 18 and the like are controlled based on the control command value.

[0080] The actuator control program is similarly executed in the drive ECU 22 , the battery ECU 24 , and the brake ECU 26 .

[0081] In this embodiment, the driving plan of the vehicle is supplied from the automatic driving controller 20 to the drive ECU 22, the battery ECU 24, the brake ECU 26, and the steering ECU 28. For example, the automatic driving controller 20 may supply a driving plan for a complete journey from the current location to the destination to these ECUs 22 to 28, or may supply a portion of the driving plan for the complete journey (e.g., a candidate driving route and a target driving value from the current location to the location to be reached after a set time). There are cases where a portion of the driving plan for the complete journey includes more than one interval, or includes a portion of one interval. Hereinafter, in this specification, the driving plan for the complete journey and a portion of the driving plan for the complete journey are both referred to as driving plans.

[0082] When the driving plan is acquired, the steering ECU 28 acquires a predicted temperature. This predicted temperature represents the state of the steering motor 18 when the vehicle is traveling according to the driving plan, that is, when the vehicle is traveling according to the candidate driving route and in accordance with the target driving value. The predicted temperature of the steering motor 18 can be acquired based on, for example, the current temperature and the amount of heat generated and dissipated by the steering motor 18 while the vehicle is traveling according to the driving plan.

[0083] For example, when a driving plan includes multiple sections, the amount of heat generated and the amount of heat dissipated by the steering motor 18 when the vehicle travels according to target driving values ​​(target driving speed, target lateral acceleration, target lateral jerk) in each of the multiple sections are obtained.

[0084] In addition, based on the target driving values ​​(target driving speed, target lateral acceleration, target lateral jerk) in each of the multiple intervals, the target steering speed, target steering torque, etc. of the vehicle's steering wheel are obtained respectively, and based on the target steering speed, target steering torque, etc. of the steering wheel, the target speed, target torque, etc. of the steering motor 18 in each of the multiple intervals are obtained respectively.

[0085] When the steering motor 18 is operated at a target speed and target torque determined based on the target driving value, the amount of heat generated by the steering motor 18 can be determined based on the current supplied to the steering motor 18, the load applied to the steering motor 18, and the like. The current supplied to the steering motor 18 is determined based on the voltage of the battery, which supplies power to the steering motor 18, the target speed, the target torque, and the like. The load applied to the steering motor 18 can be determined based on the road surface conditions, the target driving speed, and the air resistance and rolling resistance determined based on the target driving speed. Furthermore, the amount of heat dissipated by the steering motor 18 can be determined based on the outside air temperature detected by the outside air temperature sensor 32b and the wind speed applied to the steering motor 18 determined based on the target driving speed.

[0086] Furthermore, using the current temperature of the steering motor 18 detected by the motor temperature sensor 32a as an initial value, the amount of heat generated and the amount of heat dissipated by the steering motor 18 are integrated for a plurality of sections, and the difference between these values ​​is calculated to obtain a predicted temperature of the steering motor 18 when the vehicle is traveling according to the driving plan. Furthermore, by calculating the difference between the amount of heat generated and the amount of heat dissipated in each of a plurality of sections and integrating the differences for a plurality of sections, a predicted temperature of the steering motor 18 when the vehicle is traveling according to the driving plan can be obtained.

[0087] Then, when the predicted temperature is lower than or equal to the set temperature, the steering ECU 28 notifies the automatic driving controller 20 that the travel plan is permitted (permission notification).

[0088] In contrast, if the predicted temperature is higher than the set temperature, the steering ECU 28 requests the automatic driving controller 20 to modify the driving plan, that is, to re-plan the driving plan. The automatic driving controller 20 may modify the driving plan, for example, so that the maximum value of at least one of the target lateral acceleration and the target lateral jerk in at least one of the plurality of intervals is reduced, or so that the average value of at least one of the target lateral acceleration and the target lateral jerk is reduced.

[0089] To prevent overheating caused by prolonged power-on, electric motors such as the steering motor 18 are typically designed to initiate protective control and limit the motor's output when the motor's temperature exceeds a threshold temperature. This set temperature is the temperature at which operational restriction of the steering motor 18 is deemed necessary and can, for example, be determined based on the threshold temperature for initiating protective control. The set temperature can be the threshold temperature or a temperature lower than the threshold temperature.

[0090] In addition, it can be designed that when the predicted temperature is higher than the set temperature, the steering ECU 28 obtains the upper limit value of the target lateral acceleration (the upper limit value of the target steering speed) and the upper limit value of the target lateral acceleration (the upper limit value of the target steering torque) for preventing the temperature of the steering motor 18 from reaching the set temperature, and supplies at least one of the upper limit value of the target lateral acceleration and the upper limit value of the target lateral acceleration from the steering ECU 28 to the driving plan creation unit 40 of the automatic driving controller 20 in addition to the re-planning request.

[0091] In the steering ECU 28, the operation is repeatedly executed at predetermined set time intervals. Figure 2 The driving plan permission or rejection procedure is shown in the flowchart.

[0092] In S1, the driving plan provided by the automatic driving controller 20 is obtained. In S2, the target operating state of the steering motor 18 is obtained (for example, it can be expressed by a target speed, a target torque, etc.) based on the target lateral acceleration, the target lateral jerk, etc. included in the driving plan. In S3, the predicted temperature of the steering motor 18 is obtained. In S4, it is determined whether the execution of the driving plan can be achieved, that is, whether the execution of the driving plan is allowed. Specifically, it is determined whether the predicted temperature is below the set temperature. In the case of "yes", a permission notification of allowing the driving plan is provided to the automatic driving controller 20 in S5. In the case of no, a re-planning request is provided to the automatic driving controller 20 in S6 to reduce the heat generated by the steering motor 18.

[0093] Executed in the autonomous driving controller 20 Figure 3 The driving plan correction procedure is shown in the flowchart.

[0094] In S11, a determination is made as to whether a replan request has been made. If the determination is "No," S12 is not performed. If the determination is "Yes," the driving plan is modified in S12. The driving plan creation unit 40 modifies the driving plan so that the predicted temperature of the steering motor 18 is lowered, for example, the target lateral acceleration and target lateral jerk in one or more sections are reduced. Alternatively, the driving plan can be modified so that the target lateral acceleration and target lateral jerk are below an upper limit.

[0095] Then, the automatic driving is performed according to the allowed driving plan or the modified driving plan. Figure 4 The autonomous driving procedure is shown in the flowchart.

[0096] In S21, it is determined whether a permission notification has been received regarding the driving plan. If the determination is "No", it is determined in S22 whether the driving plan has been revised. If the determination in either S21 or S22 is "Yes", a control command value is created in S23 according to the driving plan and supplied to the steering ECU 28 and the like. The steering ECU 28 executes Figure 5 The actuator control program shown in the flowchart of FIG. 1 controls the steering motor 18 based on the control command value. This makes it possible to perform automatic driving in accordance with the driving plan.

[0097] As described above, in this embodiment, when there is a possibility of starting protection control for the steering motor 18, the driving plan is replanned to suppress the output of the steering motor 18. As a result, it is possible to make it difficult for the automatic driving to be stopped due to overheating of the steering motor 18.

[0098] The revised driving plan can be supplied again to the steering ECU 28. For example, the driving plan can be revised repeatedly until permission is notified. In this case, the automatic driving is performed according to the permitted driving plan.

[0099] As described above, in this embodiment, the portion storing S3 and the portion executing S3 of the steering ECU 28 of the control device 10 constitute the prediction unit, the portion storing S4 and the portion executing S4 constitute the determination unit, and the portion storing S6 and the portion executing S6 constitute the notification unit. Figure 3The driving plan correction program shown in the flowchart, the driving plan correction program execution part, etc. constitute the correction unit. And, the automatic driving controller 20 stores and executes Figure 4 The automatic driving program shown in the flowchart and the storage of the steering ECU 28 Figure 5 The portion of the actuator control program shown in the flowchart, the portion that executes the actuator control program, etc. constitute a steering actuator control unit and a steering actuator control device.

[0100] However, the control device 10 can be constituted by one computer.

[0101] In addition, part or all of the driving plan permission / rejection program can be executed in the automatic driving controller 20 .

[0102] Furthermore, the driving plan can be replanned so as to suppress overheating of not only the steering motor 18 but also the drive motor 12 and the brake actuator 16 .

[0103] The target driving state of the vehicle is not limited to the state indicated by the driving plan in the automatic driving, and may be, for example, the target driving state in the driving assistance control.

[0104] The preferred embodiments of the present invention have been described in detail above, but the present invention can be implemented in various ways with modifications and improvements based on the knowledge of those skilled in the art.

[0105] 10 ...control device; 18 ...steering motor; 20 ...automatic driving controller; 28 ...steering ECU; 40 ...driving plan creation unit; 42 ...control command value creation unit.

Claims

1. A vehicle system comprising: The vehicle-mounted device (12, 14, 16, 18) is installed in the vehicle; and A control device (10) executes a stored program to create a driving plan for the vehicle, and controls the onboard device to make the vehicle drive according to the driving plan. in, The control device is configured to predict the temperature of the vehicle-mounted device when the vehicle is traveling according to the travel plan. When the temperature of the onboard device is higher than a predetermined start threshold temperature, the output of the onboard device is limited to protect the onboard device; when the predicted temperature of the onboard device is higher than a set temperature, the driving plan is corrected; Wherein, the set temperature is lower than the predetermined starting threshold temperature, The vehicle-mounted device includes a steering actuator for steering a steering wheel of the vehicle. The driving plan includes a planned driving route and a target turning state. The target turning state includes a target lateral acceleration and a target lateral jerk, The control device is further configured as follows: predicting the temperature of the steering actuator when the vehicle travels along the planned travel route in the target turning state, When the predicted temperature of the steering actuator is higher than the set temperature, an upper limit value of the target lateral acceleration and an upper limit value of the target lateral jerk are obtained, When the predicted temperature of the steering actuator is higher than the set temperature, the driving plan is corrected so that at least one of the target lateral acceleration and the target lateral jerk is lower than at least one of an upper limit value of the target lateral acceleration and an upper limit value of the target lateral jerk.

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