Air conditioning control device, air conditioning control method, and program

Abstract

The operation of the air conditioning system is controlled according to the vehicle's driving conditions. [Solution] The air conditioning control device 30 has an air conditioning control unit 322 that controls the output of a compressor 21 included in an air conditioner 20 that conditioned the air inside the vehicle S, and the air conditioning control unit 322 makes the output of the compressor 21 when the vehicle S is accelerating less than the output of the compressor 21 when the engine brake is applied to the vehicle S.

Description

Technical Field

[0001] The present invention relates to an air conditioning control device, an air conditioning control method, and a program.

Background Art

[0002] The control device for a vehicle in Patent Document 1 operates the air conditioning device by connecting a clutch interposed between a compressor for compressing the refrigerant of the air conditioning device and an internal combustion engine, and stops the air conditioning device by disconnecting the clutch.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The air conditioning device sends cold air into the passenger compartment by rotating the compressor by the output of the internal combustion engine. However, when the output generated by the internal combustion engine (so-called output by engine brake) occurs due to a change in the depression amount of the accelerator pedal to a small depression amount, if the air conditioning device does not rotate the compressor, a loss of output due to engine brake occurs.

[0005] Therefore, the present invention has been made in view of these points, and an object thereof is to control the operation of the air conditioning device according to the running state of the vehicle.

Means for Solving the Problems

[0006] An air conditioning control device according to a first aspect of the present invention includes an air conditioning control unit that controls the output of a compressor included in an air conditioning system that provides air conditioning in the cabin of a vehicle, wherein the air conditioning control unit reduces the output of the compressor when the vehicle is accelerating to a lower value than the output of the compressor when the engine brake is applied to the vehicle.

[0007] The air conditioning control unit further comprises an acquisition unit that acquires the set temperature of the air conditioning system set by the occupant of the vehicle, the cabin temperature of the vehicle's cabin, the amount the accelerator pedal of the vehicle is pressed, and state information indicating that the vehicle is in motion; and a determination unit that determines a target temperature of the cabin based on the set temperature and the amount the pedal is pressed. The air conditioning control unit controls the output of the compressor of the air conditioning system based on a subtraction value obtained by subtracting the target temperature from the cabin temperature, and the determination unit may determine a target temperature lower than the set temperature based on the state of the vehicle included in the state information, when the amount the pedal is pressed changes from an amount greater than a predetermined amount to an amount less than or equal to a predetermined amount.

[0008] The determination unit may determine the target temperature based on the state information, which includes at least one of the following: the vehicle speed, the vehicle acceleration, the vehicle deceleration, the ambient temperature of the vehicle, and the gradient of the road surface on which the vehicle is traveling.

[0009] The determination unit may lower the target temperature as the vehicle speed decreases at the timing when the amount of pedal depression changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount.

[0010] The determination unit may lower the target temperature if the ambient temperature is higher at the time when the amount of footing changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount.

[0011] The determination unit may lower the target temperature if the deceleration is greater after the amount of footing changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount.

[0012] The determination unit may change the target temperature, which was determined to be lower than the set temperature, to the set temperature if the condition in which the road surface gradient remains downward for a predetermined time after the amount of footing changes from an amount greater than the predetermined amount to an amount less than or equal to the predetermined amount.

[0013] The determination unit may change the target temperature, which was determined to be lower than the set temperature, to the set temperature when the amount of foot pressure changes from an amount greater than the predetermined amount to an amount less than or equal to the predetermined amount and the vehicle stops, and may further change the target temperature to a higher temperature than the set temperature when the vehicle starts moving after stopping.

[0014] The determination unit may set the target temperature higher if the vehicle starts moving after coming to a stop, as the vehicle speed after departure is lower.

[0015] The determination unit may set the target temperature higher if the acceleration after the vehicle has stopped and then started moving is greater.

[0016] If the vehicle starts moving after stopping, and the road surface gradient remains uphill for a predetermined period of time, the determination unit may change the target temperature, which was determined to be higher than the set temperature, to the set temperature.

[0017] The air conditioning control unit further includes an acquisition unit for acquiring the vehicle speed, and if the acceleration based on the vehicle speed is greater than or equal to a threshold acceleration, the air conditioning control unit may disconnect the clutch connecting the vehicle's drive source and the compressor.

[0018] The air conditioning control unit may determine the disconnection time, which is the time for disengaging the clutch, to be a first time or a second time that is longer than the first time, based on the airflow levels of the air conditioning unit, which can set the airflow in multiple stages; a restriction setting indicating whether or not a restriction mode is set in which air is blown out at an airflow level lower than the airflow level corresponding to a target value for the temperature of the air blown out from the outlet of the air conditioning unit; and whether or not the interior air temperature, which is the temperature inside the vehicle, is at a temperature at which the restriction mode can be executed.

[0019] If the air conditioning control unit obtains the restriction setting indicating that the restriction mode is not set, the unit may determine the disconnection time to be the first time.

[0020] The air conditioning control unit may determine that the indoor air temperature is at a temperature at which the restriction mode cannot be executed during the period when the indoor air temperature changes from a first temperature to a second temperature lower than the first temperature, and may determine that the indoor air temperature is at a temperature at which the restriction mode can be executed during other periods different from the aforementioned period.

[0021] The air conditioning control unit may determine the cutoff time to the first time if the acquisition unit acquires the restriction setting indicating that the restriction mode has been set, and the air conditioning control unit determines that the indoor air temperature is at a temperature at which the restriction mode cannot be executed.

[0022] The air conditioning control unit may determine the cutoff time to the second time if the acquisition unit acquires the limit setting indicating that the limit mode has been set, the air conditioning control unit determines that the indoor air temperature is at a temperature at which the limit mode can be executed, and the airflow level set in the air conditioning device is below the threshold level.

[0023] The acquisition unit further acquires the amount the accelerator pedal of the vehicle is pressed, and the air conditioning control unit may increase the airflow level if the amount pressed is less than or equal to a threshold amount and the acceleration is an acceleration indicating deceleration of the vehicle.

[0024] When the stage of the air volume is greater than the threshold stage, the air conditioning control unit may maintain the stage of the air volume even if the depression amount is less than or equal to the threshold depression amount and the acceleration indicates deceleration of the vehicle.

[0025] When the acceleration is greater than or equal to the threshold acceleration, the air conditioning control unit may maintain the stage of the air volume.

[0026] The acquisition unit further acquires the internal air temperature which is the temperature inside the vehicle cabin of the vehicle, and when the acceleration based on the vehicle speed of the vehicle is greater than or equal to the threshold acceleration, the air conditioning control unit may disengage the clutch until the internal air temperature reaches a predetermined reference temperature.

[0027] The air conditioning control method according to the second aspect of the present invention includes an air conditioning control step in which an output of a compressor included in an air conditioning device that performs air conditioning in a vehicle cabin of a vehicle is made smaller in a state where the vehicle is accelerating than in a state where an engine brake is acting on the vehicle, which is executed by a processor.

[0028] The program according to the third aspect of the present invention causes a processor to execute an air conditioning control step in which an output of a compressor included in an air conditioning device that performs air conditioning in a vehicle cabin of a vehicle is made smaller in a state where the vehicle is accelerating than in a state where an engine brake is acting on the vehicle.

Effects of the Invention

[0029] According to the present invention, there is an effect of controlling the operation of the air conditioning device according to the running state of the vehicle.

Brief Description of the Drawings

[0030] [Figure 1] It is a diagram showing an outline of a vehicle S according to the first embodiment. [Figure 2] It is a diagram showing an operation in which a determination unit 323 determines a target temperature. [Figure 3] It is a diagram showing a processing sequence when an engine brake occurs. [Figure 4] This diagram shows the processing sequence when vehicle S starts moving after coming to a stop. [Figure 5] This is a diagram showing an overview of the vehicle S according to the second embodiment. [Figure 6] This figure shows an example of the operation of vehicle S according to the second embodiment. [Figure 7] This figure shows an example of a processing sequence for the air conditioning control device 30 according to the second embodiment. [Modes for carrying out the invention]

[0031] <First Embodiment> [Overview of Vehicle S] Figure 1 is a diagram showing an overview of a vehicle S according to the first embodiment. The vehicle S shown in Figure 1 includes an engine 10, a control device 11, a pedal sensor 12, a vehicle speed sensor 13, an acceleration sensor 14, a tilt angle sensor 15, an outside temperature sensor 16, a room temperature sensor 17, an operating unit 18, an air conditioner 20, and an air conditioning control device 30. The air conditioner 20 has a compressor 21, a fan 22, and an evaporator 23. The vehicle S has a function to reduce the temperature difference between the interior temperature and the set temperature by bringing the interior temperature of the vehicle S closer to the set temperature set by the occupants of the vehicle S to the air conditioner 20.

[0032] Engine 10 is an internal combustion engine that generates power by burning and expanding a mixture of fuel and intake air, and is the driving source of vehicle S. Control device 11 is a device that includes, for example, one or more ECUs (Electronic Control Units), and controls the output of engine 10 based on the operation of the driver of vehicle S. Pedal sensor 12 is a sensor for detecting the amount of depression of the accelerator pedal (not shown) operated by the driver of vehicle S.

[0033] The vehicle speed sensor 13 is a sensor for detecting the vehicle speed of vehicle S. The acceleration sensor 14 is a sensor for detecting the acceleration and deceleration of vehicle S. The tilt angle sensor 15 is a sensor for detecting the tilt angle of vehicle S in the direction of travel on the road surface on which vehicle S is traveling. The outside temperature sensor 16 is a sensor for detecting the outside temperature around vehicle S. The room temperature sensor 17 is a sensor for detecting the interior temperature of the vehicle's interior. The operation unit 18 is, for example, a display or buttons provided on the instrument panel of vehicle S. By pressing the display or buttons, the occupants of vehicle S can set a target temperature for the air conditioner 20 or adjust the airflow of the air conditioner 20.

[0034] The air conditioner 20 is a device that brings the cabin temperature of the vehicle S closer to the set temperature by sending cool or warm air into the cabin, and is a so-called air conditioner. In Figure 1, for the sake of simplicity, the configuration for the air conditioner 20 to send cool air into the cabin is shown. The compressor 21 is a compressor that rotates with the driving force of the engine 10 at a rotational speed corresponding to the output of the compressor 21 determined by the air conditioning control device 30, and compresses the vaporized refrigerant. The refrigerant compressed by the compressor 21 is liquefied by a condenser (not shown), then sprayed by an expansion valve (not shown) to cool and vaporize it, and sent to the evaporator 23 as cooling air.

[0035] Fan 22 is a blower fan that takes in air from the passenger compartment of vehicle S or outside air surrounding vehicle S as intake air and discharges it to the evaporator 23. The evaporator 23 cools the intake air discharged by fan 22 by exchanging heat between the cooling air generated by the refrigerant compressed by the compressor 21 and the intake air, and then discharges it into the passenger compartment of vehicle S. By operating as described above, the air conditioner 20 can lower the passenger compartment temperature as the output of the compressor 21 increases, as it makes it easier to cool the intake air. Furthermore, the air conditioner 20 can increase the airflow as the rotation speed of fan 22 increases.

[0036] The air conditioning control device 30 controls the output of the compressor 21 based on the set temperature set by the occupant of the vehicle S using the control unit 18, and controls the rotation speed of the fan 22 based on the airflow adjusted by the occupant of the vehicle S using the control unit 18. The air conditioning control device 30 is a housing containing electronic components or a printed circuit board on which electronic components are mounted.

[0037] Since the compressor 21 rotates due to the driving force of the engine 10, if the compressor 21 rotates when the vehicle S is accelerating, the vehicle S will have difficulty accelerating. Also, when the driver reduces the pressure on the accelerator pedal to decelerate the vehicle S, creating resistance to the engine 10's drive (a state known as engine braking), the engine 10 will continue to drive even if fuel is not injected into it. In this state, if the compressor 21 does not rotate, the engine 10 will incur power loss due to engine braking.

[0038] Therefore, the air conditioning control device 30 determines the target temperature of the vehicle cabin based on the set temperature and the amount the accelerator pedal is pressed, and increases the output of the compressor 21 as the temperature difference between the vehicle cabin temperature and the target temperature increases. Furthermore, the air conditioning control device 30 makes the output of the compressor 21 when the vehicle S is accelerating less than the output of the compressor 21 when engine braking is applied to the vehicle S. Specifically, if the air conditioning control device 30 determines that engine braking has occurred based on the amount the accelerator pedal is pressed, it determines a target temperature lower than the set temperature.

[0039] By operating in this manner, the air conditioning control device 30 can reduce the loss of engine power 10 by using the output of engine braking generated when the vehicle S decelerates to rotate the compressor 21 and lower the cabin temperature. Furthermore, the air conditioning control device 30 can set the cabin temperature to a target temperature lower than the set temperature by using the output of engine braking to rotate the compressor 21 and bring the cabin temperature closer to the target temperature. Therefore, when the vehicle S accelerates after engine braking occurs, if the cabin temperature is lower than the set temperature, the air conditioning control device 30 can stop the compressor 21 or reduce the output of the compressor 21. As a result, the air conditioning control device 30 can make it easier to accelerate the vehicle S.

[0040] In addition, the air conditioning control device 30 determines the target temperature based on the state of the vehicle S. The state of the vehicle S includes, for example, the speed of the vehicle S, the acceleration / deceleration of the vehicle S, the ambient temperature of the vehicle S, and the gradient of the road surface on which the vehicle S is traveling. By operating in this manner, the air conditioning control device 30 can determine the target temperature based on estimation results, such as whether engine braking is likely to continue, whether the vehicle S is likely to continue accelerating, and whether the cabin temperature is likely to rise. As a result, the air conditioning control device 30 can control the output of the compressor 21 with high precision so as to suppress losses in the engine 10 and to allow the vehicle S to accelerate easily. The configuration and operation of the air conditioning control device 30 will be described in detail below.

[0041] [Configuration of the air conditioning control device 30] As shown in Figure 1, the air conditioning control device 30 has a storage unit 31 and a control unit 32. The control unit 32 has an acquisition unit 321, an air conditioning control unit 322, and a determination unit 323.

[0042] The memory unit 31 has a storage medium such as ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), or SSD (Solid State Drive). The memory unit 31 stores a program for the control unit 32 to execute. The memory unit 31 also stores various information for determining the output of the compressor 21 and the rotation speed of the fan 22.

[0043] The control unit 32 is, for example, a processor such as a CPU (Central Processing Unit). The control unit 32 functions as the acquisition unit 321, the air conditioning control unit 322, and the determination unit 323 by executing the program stored in the storage unit 31. The control unit 32 may consist of one processor, or it may consist of multiple processors or a combination of one or more processors and electronic circuits.

[0044] The acquisition unit 321 acquires the set temperature of the air conditioner 20 set by the occupant of the vehicle S, the cabin temperature of the vehicle S's passenger compartment, the amount the accelerator pedal of the vehicle S is pressed, and status information indicating the state of the vehicle S in motion. The status information includes, for example, at least one of the following: the vehicle speed of the vehicle S, the acceleration of the vehicle S, the deceleration of the vehicle S, the outside temperature of the vehicle S, and the gradient of the road surface on which the vehicle S is traveling.

[0045] The acquisition unit 321 acquires, for example, the set temperature set by the occupant of the vehicle S operating the control unit 18. The acquisition unit 321 acquires, for example, airflow information indicating the size of the airflow set by the occupant operating the control unit 18. For example, the size of the airflow can be "strong", "medium", or "weak". The acquisition unit 321 acquires, for example, the cabin temperature detected by the room temperature sensor 17. The acquisition unit 321 acquires, for example, the amount the accelerator pedal is depressed detected by the pedal sensor 12 via the control device 11.

[0046] The acquisition unit 321 acquires, for example, state information indicating the vehicle speed detected by the vehicle speed sensor 13 via the control device 11. The acquisition unit 321 acquires, for example, state information indicating the acceleration or deceleration detected by the acceleration sensor 14 via the control device 11. The acquisition unit 321 acquires, for example, state information indicating the outside temperature detected by the outside temperature sensor 16. The acquisition unit 321 may also acquire state information indicating the outside temperature via the control device 11. The acquisition unit 321 acquires, for example, state information indicating the gradient (uphill, downhill, or flat) of the road surface on which the vehicle S is traveling, which is determined by the control device 11 based on the inclination angle of the direction of travel of the vehicle S detected by the inclination angle sensor 15.

[0047] The air conditioning control unit 322 controls the rotation speed of the fan 22 of the air conditioner 20. For example, the air conditioning control unit 322 rotates the fan 22 at a rotation speed corresponding to the magnitude of the airflow included in the airflow information acquired by the acquisition unit 321. The air conditioning control unit 322 controls the output (rotation speed) of the compressor 21 of the air conditioner 20. Based on the subtraction value obtained by subtracting the target temperature from the cabin temperature acquired by the acquisition unit 321, the air conditioning control unit 322 controls the output of the compressor 21 included in the air conditioner 20 that provides air conditioning in the cabin of the vehicle S. The target temperature is the temperature corresponding to the set temperature acquired by the acquisition unit 321 and is determined by the determination unit 323. Details of the target temperature will be described later.

[0048] The air conditioning control unit 322 divides the range of possible values ​​for the subtraction value into multiple subdivision ranges, and causes the compressor 21 to output an output corresponding to the subdivision range that includes the subtraction value. Specifically, if the absolute value of the subtraction value is less than a predetermined value, the air conditioning control unit 322 causes the compressor 21 to output a first output. If the absolute value is greater than or equal to the predetermined value and the cabin temperature is greater than the target temperature, the air conditioning control unit 322 causes the compressor 21 to output a second output greater than the first output. If the absolute value is greater than or equal to the predetermined value and the cabin temperature is less than the target temperature, the air conditioning control unit 322 causes the compressor 21 to output a third output less than the first output. The predetermined value is, for example, 1°C.

[0049] In addition to the above operations, the air conditioning control unit 322 may increase the output of the compressor 21 as the subtraction value increases. The air conditioning control unit 322 may stop the operation of the compressor 21 to prevent overcooling of the vehicle interior if the cabin temperature is lower than the target temperature. The air conditioning control unit 322 may stop the operation of the compressor 21 and accelerate the vehicle interior if it determines that the vehicle S is accelerating based on the amount of accelerator pedal depression acquired by the acquisition unit 321.

[0050] The determination unit 323 determines the target temperature of the vehicle cabin based on the set temperature acquired by the acquisition unit 321 and the amount of accelerator pedal depression. The determination unit 323 determines a target temperature lower than the set temperature because the amount of depression has changed from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount. The predetermined amount is the amount at which resistance occurs in the driving of the engine 10 (the amount at which so-called engine braking occurs), and for example, it is zero. In other words, the determination unit 323 determines a target temperature lower than the set temperature because engine braking has occurred.

[0051] Figure 2 shows the operation of the determination unit 323 in determining the target temperature. The horizontal axis in Figure 2 represents time. The vertical axis in Figure 2 shows "Depression Amount" indicating the amount the accelerator pedal is pressed, "Vehicle Speed" indicating the vehicle speed of vehicle S, "Temperature" indicating the target temperature and cabin temperature, "Compressor Output" indicating the output of compressor 21, and "Air Conditioner Load" indicating the load of air conditioner 20. In "Temperature" shown in Figure 2, the target temperature is shown by a solid line, and the cabin temperature is shown by a dashed line. In Figure 2, the set temperature is temperature M1.

[0052] At time T1 shown in Figure 2, the determination unit 323 determines a target temperature M2 that is lower than the set temperature M1 because the amount of pedal depression P1 has changed from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount P2. As a result, the subtraction value obtained by subtracting the target temperature M2 from the cabin temperature (temperature M1) changes from zero to a predetermined value or greater. Therefore, the air conditioning control unit 322 increases the output of the compressor 21 to output C2 using the output generated by engine braking between time T1 and time T2, thereby lowering the cabin temperature from temperature M1 to temperature M2. As a result, the vehicle S can use the output generated by engine braking to operate the air conditioner 20, thus suppressing the loss of said output.

[0053] Furthermore, the air conditioning control unit 322 can lower the cabin temperature when engine braking is applied by using the output generated by engine braking to operate the air conditioner 20. As a result, since the cabin temperature is lowered during acceleration after engine braking, the air conditioning control unit 322 can set the output of the compressor 21 when the vehicle S is accelerating to be lower than the output of the compressor 21 when engine braking is applied to the vehicle S.

[0054] The determination unit 323 determines the target temperature based on the state of the vehicle S included in the state information acquired by the acquisition unit 321. For example, the determination unit 323 lowers the target temperature the smaller the vehicle speed at the timing when the amount of accelerator pedal depression changes from an amount greater than a predetermined amount to an amount less than or equal to a predetermined amount (time T1 shown in Figure 2). For example, the determination unit 323 increases the output of the compressor 21 controlled by the air conditioning control unit 322 by increasing the subtraction value obtained by subtracting the target temperature from the cabin temperature the smaller the vehicle speed at time T1 shown in Figure 2. The determination unit 323 may also lower the target temperature if the vehicle speed at time T1 is less than a vehicle speed threshold stored in the storage unit 31. The vehicle speed threshold is, for example, the maximum speed of a vehicle S traveling on a congested road (for example, 30 km / h).

[0055] The lower the vehicle speed when engine braking occurs, the shorter the time it takes for the vehicle S to decelerate. Therefore, when the determination unit 323 operates as described above, the air conditioning control unit 322 can increase the output of the compressor 21 to lower the cabin temperature in a short time if the time during which engine braking occurs is short. As a result, the vehicle S can more easily suppress the power loss caused by engine braking.

[0056] The determination unit 323 may lower the target temperature if the ambient temperature is high at the time when the amount of accelerator pedal depression changes from an amount greater than a predetermined amount to an amount less than or equal to a predetermined amount. For example, the determination unit 323 increases the output of the compressor 21 controlled by the air conditioning control unit 322 by increasing the subtraction value obtained by subtracting the target temperature from the cabin temperature if the ambient temperature at time T1 shown in Figure 2 is high. The determination unit 323 may lower the target temperature if the ambient temperature at time T1 is above a temperature threshold stored in the memory unit 31. The temperature threshold is, for example, 25°C. By operating as described above, the air conditioning control unit 322 can cool the cabin more easily when the ambient temperature is high, thus preventing the cabin temperature from rising due to the ambient temperature and failing to reach the target temperature.

[0057] The determination unit 323 may lower the target temperature if the deceleration after the accelerator pedal depression changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount is greater. For example, the determination unit 323 increases the output of the compressor 21 controlled by the air conditioning control unit 322 by increasing the subtraction value obtained by subtracting the target temperature from the cabin temperature if the deceleration acquired by the acquisition unit 321 between time T1 and time T2 as shown in Figure 2 is greater. The determination unit 323 may lower the target temperature if the deceleration between time T1 and time T2 is greater than or equal to the deceleration threshold stored in the memory unit 31. The deceleration threshold is a threshold determined by experiment or simulation.

[0058] The greater the deceleration, the shorter the time it takes for the vehicle S to come to a stop, thus reducing the time during which engine braking occurs. As a result, the determination unit 323 operates as described above, allowing the air conditioning control unit 322 to increase the output of the compressor 21 and lower the cabin temperature in a shorter time as the time during which engine braking occurs decreases. Consequently, the vehicle S can use the output of the engine 10 generated by engine braking to bring the cabin temperature closer to the target temperature, and the time during which the compressor 21 is driven by the output of the engine 10 when engine braking is not occurring can be reduced.

[0059] The determination unit 323 may change the target temperature, which has been determined to be lower than the set temperature, to the set temperature if the road surface gradient remains downhill for a predetermined time after the amount of accelerator pedal depression changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount. The predetermined time is, for example, an estimated value of the time from the time when the air conditioner 20 starts operating until the time when the cabin temperature reaches the target temperature, and is stored in the storage unit 31. For example, if the road surface gradient acquired by the acquisition unit 321 at each unit time (for example, 0.1 seconds) during the predetermined time from time T1 shown in Figure 2 indicates a downhill slope, the determination unit 323 changes the target temperature from temperature M2 to temperature M1.

[0060] When the road surface on which vehicle S is traveling is on a downhill slope, the amount the accelerator pedal is pressed tends to be smaller, making engine braking more likely. Therefore, if the downhill slope continues, there is a risk of overcooling the passenger compartment if the compressor 21 continues to operate using the output generated by engine braking. Therefore, when the determination unit 323 operates as described above, the subtraction value obtained by subtracting the target temperature from the passenger compartment temperature becomes zero, so the air conditioning control unit 322 can reduce the output of the compressor 21 and suppress overcooling of the passenger compartment.

[0061] The determination unit 323 changes the target temperature, which was determined to be lower than the set temperature, to the set temperature when, for example, the amount of accelerator pedal depression changes from an amount greater than a predetermined amount to an amount less than or equal to a predetermined amount, and then the vehicle S comes to a stop. The determination unit 323 determines that the vehicle S has come to a stop when, for example, the vehicle speed acquired by the acquisition unit 321 at time T2 shown in Figure 2 shows vehicle speed V2 (zero). Then, the determination unit 323 changes the target temperature M2 determined at time T1 to target temperature M1 at time T2.

[0062] By operating in this manner, the air conditioning control unit 322 can reduce the output of the compressor 21 and thus reduce the load on the air conditioner 20 when the vehicle S is stopped and no engine braking occurs (the state between time T2 and time T3 shown in Figure 2). As a result, the output of the engine 10 can be reduced while the vehicle S is stopped.

[0063] The determination unit 323 further changes the target temperature to one higher than the set temperature, for example, if the vehicle S starts moving after coming to a stop. For example, the determination unit 323 determines that the vehicle S started moving after coming to a stop because the amount of accelerator pedal depression acquired by the acquisition unit 321 at time T3 shown in Figure 2 changed from depression amount P2 to depression amount P3. Then, the determination unit 323 changes the target temperature M1 determined at time T2 to target temperature M3 at time T3.

[0064] By operating in this manner, the air conditioning control unit 322 can reduce or stop the output of the compressor 21 when the vehicle S is accelerating (the state between time T3 and time T4 shown in Figure 2) because the target temperature is higher than the cabin temperature. As a result, the output of the engine 10 when the vehicle S is accelerating can be more easily used for acceleration, making it easier to accelerate the vehicle S.

[0065] Furthermore, in vehicle S, the cabin temperature is lowered using the output D1 generated by engine braking between time T1 and time T2. Therefore, between time T2 and time T4, the cabin temperature will be below temperature M1 even without the air conditioner 20 lowering the cabin temperature. As a result, after time T4 (after acceleration due to starting is completed), vehicle S can maintain the cabin temperature below the target temperature without increasing the output of the compressor 21 using the output D2 of the engine 10.

[0066] The determination unit 323 may set the target temperature higher the lower the vehicle speed after departure, if the vehicle S has stopped and then started moving. For example, the determination unit 323 makes it difficult for the air conditioning control unit 322 to increase the output of the compressor 21 by setting the target temperature higher the lower the vehicle speed of the vehicle S is at a time after time T3 shown in Figure 2. The determination unit 323 may also set the target temperature higher if the vehicle speed at a time after time T3 is less than the vehicle speed threshold stored in the storage unit 31.

[0067] Vehicle S traveling on ordinary roads travels at a lower speed than vehicle S traveling on expressways, and is more likely to stop at traffic lights or stop signs, resulting in shorter acceleration times and more frequent engine braking. Therefore, when the determination unit 323 operates as described above, the subtraction value obtained by subtracting the target temperature from the cabin temperature becomes smaller during acceleration on ordinary roads, making it easier for the air conditioning control unit 322 to reduce the output of the compressor 21 when vehicle S is accelerating. Furthermore, because the cabin temperature rises due to the air conditioning control unit 322 not cooling the cabin when vehicle S is accelerating, it becomes easier to use the output from engine braking to operate the compressor 21 when vehicle S is decelerating.

[0068] The determination unit 323 may set the target temperature higher if the vehicle S starts after coming to a stop, and the acceleration after departure is greater. For example, the determination unit 323 makes it difficult for the air conditioning control unit 322 to increase the output of the compressor 21 by setting the target temperature higher if the acceleration acquired by the acquisition unit 321 is greater at a time later than time T3 shown in Figure 2. The determination unit 323 may also set the target temperature higher if the acceleration at a time later than time T3 is greater than or equal to the acceleration threshold stored in the storage unit 31. The acceleration threshold is a threshold determined by experiment or simulation.

[0069] The greater the acceleration, the easier it is for the vehicle speed to reach the speed limit, resulting in a shorter acceleration time and increased engine braking. Therefore, by operating the determination unit 323 as described above, the air conditioning control unit 322 can reduce the output of the compressor 21 during short acceleration times, making it easier for the vehicle S to accelerate. Furthermore, when the vehicle S decelerates, the air conditioning control unit 322 can increase the output of the compressor 21 using the output generated by engine braking, thereby suppressing the loss of output caused by engine braking.

[0070] The determination unit 323 may change the target temperature, which has been determined to be higher than the set temperature, to the set temperature if the vehicle S starts moving after stopping, and the road surface gradient after departure remains uphill for a predetermined period of time. For example, if the road surface gradient acquired by the acquisition unit 321 at each unit time during a predetermined period from time T3 as shown in Figure 2 indicates an uphill gradient, the determination unit 323 changes the target temperature from temperature M3 to temperature M1. When the road surface on which the vehicle S is traveling is uphill, engine braking becomes less likely to occur. Therefore, by operating as described above, the determination unit 323 makes it easier for the air conditioning control unit 322 to increase the output of the compressor 21, even when engine braking is less likely to occur.

[0071] [Processing sequence in the air conditioning control device 30] Figures 3 and 4 show an example of a processing sequence in which the air conditioning control device 30 determines the target temperature. Figure 3 shows the processing sequence when engine braking occurs, and Figure 4 shows the processing sequence when the vehicle S starts moving after coming to a stop.

[0072] First, the operation to determine the target temperature when engine braking occurs will be explained using Figure 3. The acquisition unit 321 acquires the set temperature and status information (step S11). The determination unit 323 determines the target temperature by subtracting the subtraction temperature from the set temperature acquired by the acquisition unit 321 (step S12). The subtraction temperature is, for example, a temperature of 5°C or less and is stored in the storage unit 31.

[0073] If the vehicle speed included in the state information is less than the vehicle speed threshold (YES in step S13), the decision unit 323 further subtracts the subtraction temperature from the target temperature determined in step S12 (step S14). If the vehicle speed is equal to or greater than the vehicle speed threshold (NO in step S13), the decision unit 323 decides to maintain the target temperature determined in step S12. If the ambient temperature included in the state information is equal to or greater than the temperature threshold (YES in step S15), the decision unit 323 further subtracts the subtraction temperature from the target temperature (step S16). If the ambient temperature is less than the temperature threshold (NO in step S15), the decision unit 323 decides to maintain the target temperature.

[0074] The acquisition unit 321 acquires further state information (step S17) and updates the state information acquired in step S11. By updating in this way, the decision unit 323 can acquire the state in which the vehicle S is running at a time after the timing when engine braking occurs. If the deceleration included in the state information is greater than or equal to the deceleration threshold (YES in step S18), the decision unit 323 further subtracts the subtracted temperature from the target temperature (step S19). If the deceleration is less than the deceleration threshold (NO in step S18), the decision unit 323 decides to maintain the target temperature.

[0075] If the decision unit 323 determines that the road surface gradient included in the status information indicates a downhill gradient and that the downhill gradient continues for a predetermined time (YES in step S20), it changes the target temperature to the set temperature acquired by the acquisition unit 321 (step S23). If the downhill gradient does not continue for a predetermined time (NO in step S20), the acquisition unit 321 acquires further status information (step S21), and after updating the status information acquired in step S17, the decision unit 323 determines whether or not the vehicle S has stopped (step S22). If it determines that the vehicle S has not stopped (NO in step S22), the decision unit 323 returns to the process in step S20. If it determines that the vehicle S has stopped (YES in step S22), the decision unit 323 terminates the process.

[0076] Next, the operation of determining the target temperature when vehicle S starts moving after coming to a stop will be explained using Figure 4. The acquisition unit 321 acquires the set temperature and state information (step S31). The determination unit 323 determines the target temperature by adding an additional temperature to the set temperature acquired by the acquisition unit 321 (step S32). The additional temperature is, for example, a temperature of 5°C or less and is stored in the storage unit 31. If the vehicle speed included in the state information is less than the vehicle speed threshold (YES in step S33), the determination unit 323 further adds the additional temperature to the target temperature determined in step S32 (step S34). If the vehicle speed is equal to or greater than the vehicle speed threshold (NO in step S33), the determination unit 323 decides to maintain the target temperature determined in step S32.

[0077] The acquisition unit 321 acquires further state information (step S35) and updates the state information acquired in step S31. By updating in this way, the decision unit 323 can acquire the state in which vehicle S is running at a time later than when vehicle S started to depart. If the acceleration included in the state information is greater than or equal to the acceleration threshold (YES in step S36), the decision unit 323 adds the additional temperature to the target temperature (step S37). If the acceleration is less than the acceleration threshold (NO in step S36), the decision unit 323 decides to maintain the target temperature.

[0078] If the decision unit 323 determines that the road surface gradient included in the state information is an uphill gradient and that the uphill gradient continues for a predetermined time (YES in step S38), it changes the target temperature to the set temperature acquired by the acquisition unit 321 (step S41). If the uphill gradient does not continue for a predetermined time (NO in step S38), the acquisition unit 321 acquires further state information (step S39), and after updating the state information acquired in step S35, the decision unit 323 determines whether or not the vehicle S has finished accelerating (step S40). If it determines that the vehicle has not finished accelerating (NO in step S40), the decision unit 323 returns to the process in step S38. If it determines that the vehicle S has finished accelerating (YES in step S40), the decision unit 323 terminates the process.

[0079] [Effects of the air conditioning control device 30 according to the first embodiment] As described above, the air conditioning control device 30 includes an acquisition unit 321 that acquires the set temperature of the air conditioner 20 set by the occupant of the vehicle S, the cabin temperature of the vehicle S's passenger compartment, the amount the accelerator pedal of the vehicle S is pressed, and state information indicating the state in which the vehicle S is running; a determination unit 323 that determines the target temperature of the passenger compartment based on the set temperature and the amount pressed; and an air conditioning control unit 322 that controls the output of the compressor 21 of the air conditioner 20 based on a subtraction value obtained by subtracting the target temperature from the cabin temperature. The determination unit 323 then determines a target temperature lower than the set temperature based on the state of the vehicle S included in the state information, when the amount pressed changes from an amount greater than a predetermined amount to an amount less than or equal to a predetermined amount.

[0080] With the air conditioning control device 30 configured in this way, the compressor 21 can be rotated by the output of engine braking generated when the vehicle S decelerates, thereby lowering the cabin temperature and reducing the power loss of the engine 10. Furthermore, the air conditioning control device 30 can rotate the compressor 21 by the output of engine braking, bringing the cabin temperature closer to a target temperature lower than the set temperature, so that the cabin temperature when the vehicle S accelerates after engine braking occurs can be kept below the set temperature. For this reason, the air conditioning control device 30 can reduce the output of the compressor 21 when the vehicle S accelerates after engine braking occurs, making it easier to accelerate the vehicle S.

[0081] In addition, the air conditioning control device 30 can determine the target temperature based on the ease with which the vehicle's interior temperature rises and the driving state of the vehicle S, by determining the target temperature based on the status information. As a result, the air conditioning control device 30 can control the output of the compressor 21 with high precision so that the vehicle S can accelerate easily.

[0082] <Second Embodiment> In the second embodiment, an example will be described in which the air conditioning control device 30 controls the temperature inside the vehicle S by controlling the output of the compressor 21 and the rotation speed of the fan 22, without having a determination unit 323 for determining the target temperature.

[0083] [Overview of Vehicle S in the Second Embodiment] Figure 5 shows an overview of a vehicle S according to the second embodiment. The vehicle S shown in Figure 5 differs from the vehicle S shown in Figure 1 in that it does not have an acceleration sensor 14 and a tilt angle sensor 15, but is otherwise the same. Furthermore, the air conditioner 20 shown in Figure 5 differs from the air conditioner 20 shown in Figure 1 in that it further has a motor 24 and a clutch 25, but is otherwise the same. The air conditioning control device 30 shown in Figure 5 differs from the air conditioning control device 30 shown in Figure 1 in that it does not have a determination unit 323, but is otherwise the same. Although not shown in Figure 1, the air conditioner 20 shown in Figure 1 has an air outlet 26, just like the air conditioner 20 shown in Figure 5. Furthermore, the air conditioner 20 shown in Figure 1 may also have a motor 24 and a clutch 25, just like the air conditioner 20 shown in Figure 5.

[0084] Motor 24 is an electric motor that rotates fan 22 by converting electrical energy (power) supplied from a power storage device (not shown) provided by vehicle S into mechanical energy. For example, motor 24 receives power at a voltage corresponding to the airflow stage determined by the air conditioning control device 30 from among multiple airflow stages that can be set in the air conditioner 20 (air conditioning system) which has a multi-stage airflow setting. Motor 24 may also receive power adjusted by PWM (Pulse Width Modulation) corresponding to the airflow stage determined by the air conditioning control device 30 from among multiple airflow stages. Then, motor 24 rotates fan 22 with the supplied power. By operating in this manner, the air conditioner 20 can blow air at an airflow rate corresponding to the stage determined by the air conditioning control device 30 into the vehicle interior from the air outlet 26.

[0085] The clutch 25 is a power transmission device installed between the engine 10, which is the drive source of the vehicle S, and the compressor 21, and controls whether or not to transmit power from the engine 10 to the compressor 21. The compressor 21 receives power from the engine 10 when the clutch 25 is engaged, for example, and the power from the engine 10 is cut off when the clutch 25 is disengaged.

[0086] The air conditioning control device 30 sets the airflow level on the air conditioner 20, causing it to blow air out from the air outlet 26 of the air conditioner 20 at an airflow level corresponding to the set level. The air conditioning control device 30 determines, for example, a target discharge temperature, which is a target value for the temperature of the air blown out from the air outlet 26 of the air conditioner 20, and increases the level as the target discharge temperature decreases. The air conditioning control device 30 lowers the target discharge temperature as the outside temperature around the vehicle S detected by the outside temperature sensor 16 (hereinafter referred to as "outside temperature") increases. The air conditioning control device 30 may also lower the target discharge temperature as the temperature inside the vehicle S detected by the room temperature sensor 17 (hereinafter referred to as "inside temperature") increases, or it may lower the target discharge temperature as the set temperature set by the occupant of the vehicle S operating the control unit 18 decreases.

[0087] The air conditioning control device 30 determines the airflow stage based on a limit setting indicating whether or not a limit mode (so-called ECO mode) has been set, which blows out air at an airflow stage lower than the stage corresponding to the target discharge temperature. For example, if an occupant of the vehicle S sets a limit mode by operating the control unit 18, the air conditioning control device 30 obtains a limit setting from the control unit 18 indicating that a limit mode has been set, and then determines an airflow stage lower than the stage corresponding to the target discharge temperature. On the other hand, if an occupant of the vehicle S releases a limit mode by operating the control unit 18, the air conditioning control device 30 obtains a limit setting from the control unit 18 indicating that a limit mode has been released, and then determines an airflow stage corresponding to the target discharge temperature.

[0088] As the interior temperature of vehicle S rises, setting the airflow level based on the restriction mode to the air conditioner 20 makes it more difficult to lower the interior temperature. Therefore, when the air conditioning control device 30 acquires a restriction setting indicating that a restriction mode has been set, it further determines whether the interior temperature is at a temperature at which the restriction mode can be executed (i.e., whether a cool-down is necessary). For example, if the air conditioning control device 30 determines that the interior temperature is not suitable for executing the restriction mode, it will not execute the restriction mode even if it acquires a restriction setting indicating that a restriction mode has been set. Details of how the air conditioning control device 30 determines whether the interior temperature is suitable for executing the restriction mode will be described later.

[0089] As shown in Figure 5, the compressor 21 rotates due to the driving force of the engine 10. Therefore, when the vehicle S is accelerating, if the compressor 21 rotates, the vehicle S will have difficulty accelerating. Also, when engine braking is applied to the vehicle S, the engine 10 is driven even without fuel injection. Therefore, if the compressor 21 does not rotate, or if the output of the compressor 21 is small, a loss of output from the engine 10 occurs.

[0090] Therefore, the air conditioning control device 30 reduces the output of the compressor 21 when the vehicle S is accelerating to less than the output of the compressor 21 when engine braking is applied to the vehicle S. Specifically, the air conditioning control device 30 increases the airflow level of the air conditioner 20 when engine braking is applied to the vehicle S to more than the airflow level of the air conditioner 20 when the vehicle S is accelerating. Then, when the vehicle S is accelerating, the air conditioning control device 30 disengages the clutch 25.

[0091] By operating as described above, the air conditioning control device 30 can interrupt the power from the engine 10 transmitted to the compressor 21 when the vehicle S is accelerating, thereby making it easier to accelerate the vehicle S. Furthermore, the air conditioning control device 30 can transmit power from the engine 10 to the compressor 21 when engine braking is applied to the vehicle S, thereby suppressing the loss of power from the engine 10.

[0092] Furthermore, the air conditioning control device 30 acquires a limit setting indicating that a limit mode has been set, and determines whether the following conditions are met: the interior air temperature is such that the limit mode can be executed, and the airflow level set on the air conditioner 20 is below a threshold level. The threshold level is, for example, a predetermined maximum value of an appropriate airflow level. If these conditions are met, the air conditioning control device 30 may extend the time for which the clutch 25 is disengaged while the vehicle S is accelerating compared to when the conditions are not met. By operating in this manner, it becomes easier to further accelerate the vehicle S when there is no need to rapidly lower the interior air temperature of the vehicle S. The configuration and operation of the air conditioning control device 30 will be described in detail below.

[0093] [Configuration of the air conditioning control device 30 in the second embodiment] As shown in Figure 5, the air conditioning control device 30 has a storage unit 31 and a control unit 32. The control unit 32 has an acquisition unit 321 and an air conditioning control unit 322. The storage unit 31 and the control unit 32 are the same as the storage unit 31 and the control unit 32 shown in Figure 1.

[0094] The acquisition unit 321 acquires the amount the accelerator pedal of the vehicle S is pressed (so-called accelerator opening) detected by the pedal sensor 12 and the vehicle speed of the vehicle S detected by the vehicle speed sensor 13 via the control device 11. The acquisition unit 321 may acquire the amount the accelerator pedal of the vehicle S is pressed and the vehicle speed of the vehicle S without going through the control device 11.

[0095] The acquisition unit 321 acquires the outside air temperature, which is the outside air temperature around the vehicle S detected by the outside air temperature sensor 16, and the inside air temperature, which is the temperature inside the vehicle S detected by the room temperature sensor 17. The acquisition unit 321 acquires from the operation unit 18 a restriction setting indicating whether or not the occupant of the vehicle S has set a restriction mode by operating the operation unit 18. The acquisition unit 321 may also acquire from the operation unit 18 a set temperature, which is the target value of the inside air temperature set by the occupant of the vehicle S by operating the operation unit 18.

[0096] The air conditioning control unit 322 controls the airflow levels of the air conditioner 20 (air conditioning system) that provides air conditioning in the vehicle S, with the airflow being adjustable in multiple stages. For example, after determining one of the multiple airflow levels that can be set for the air conditioner 20, the air conditioning control unit 322 supplies power at a voltage corresponding to that stage, or power adjusted by PWM corresponding to that stage, from the energy storage device to the motor 24. By operating in this manner, the motor 24 is driven to rotate the fan 22 at a rotational speed corresponding to that stage, so that the air conditioning control unit 322 can set the airflow levels of the air conditioner 20 in multiple stages.

[0097] The air conditioning control unit 322, for example, determines a target discharge temperature, which is a target value for the temperature of the air blown out from the air outlet 26 of the air conditioner 20, and then increases the airflow level of the air conditioner 20 as the target discharge temperature decreases. The air conditioning control unit 322 determines the target discharge temperature, which is a target value for the temperature of the air blown out from the air outlet 26 of the air conditioner 20, based on at least one of the outside air temperature, inside air temperature, and set temperature acquired by the acquisition unit 321, for example. Specifically, the air conditioning control unit 322 lowers the target discharge temperature as the outside air temperature increases. The air conditioning control unit 322 may also lower the target discharge temperature as the inside air temperature increases, or as the set temperature decreases.

[0098] Furthermore, the air conditioning control unit 322 may determine the airflow level of the air conditioner 20 based on whether or not engine braking is being applied to the vehicle S. For example, if the amount of accelerator pedal depression acquired by the acquisition unit 321 is less than or equal to a threshold depression amount, and the acceleration of the vehicle S is an acceleration indicating deceleration of the vehicle S, the air conditioning control unit 322 determines that engine braking is being applied to the vehicle S and increases the airflow level. The threshold depression amount is stored in the storage unit 31 and is the maximum amount of depression when the vehicle S is decelerating, and is zero as an example. Based on the vehicle speed of the vehicle S acquired by the acquisition unit 321 at multiple time points, the air conditioning control unit 322 determines whether or not the acceleration of the vehicle S is an acceleration indicating deceleration.

[0099] Figure 6 shows an example of the operation of vehicle S according to the second embodiment. The horizontal axis in Figure 6 represents time. The vertical axis in Figure 6 shows the limit setting, indicating whether or not the limit mode is set; the temperature state, indicating whether or not the interior temperature is suitable for executing the limit mode; the airflow level; the vehicle speed of vehicle S; the amount the accelerator pedal is depressed; and whether or not the clutch 25 is engaged. ON in Figure 6 indicates that the occupant of vehicle S has set the limit mode, and OFF in Figure 6 indicates that the occupant has released the limit mode. CD in Figure 6 indicates an interior temperature state in which the limit mode cannot be executed, and NCD in Figure 6 indicates an interior temperature state in which the limit mode can be executed. In Figure 6, the larger the numerical value, the greater the airflow.

[0100] During the time period from time Ti to time Tj shown in Figure 6, the air conditioning control unit 322 determines that the accelerator pedal is depressed to less than or equal to the threshold depression amount (zero) and that the vehicle speed has decreased from V11 to V12, indicating that engine braking is being applied to the vehicle S. Having determined that engine braking is being applied to the vehicle S, the air conditioning control unit 322 increases the airflow level of the air conditioner 20 from "1" to "2". By operating in this manner, the air conditioning control unit 322 can increase the output of the air conditioner 20 during times when the vehicle S does not require power for driving.

[0101] At the time when it is determined that engine braking is being applied to the vehicle S, the airflow level of the air conditioner 20 may have increased due to a decrease in the target outlet temperature. In this case, if the airflow level is increased further, the loudness of the air blown out from the outlet 26 and the large volume of air blown out from the outlet 26 may cause discomfort to the occupants. Therefore, even if the air conditioning control unit 322 determines that engine braking is being applied to the vehicle S, it may maintain the airflow level of the air conditioner 20 if it has reached a predetermined level (for example, level 2 shown in Figure 6).

[0102] The air conditioning control unit 322 maintains the airflow level even if the accelerator pedal is depressed to less than or equal to the threshold depression amount and the acceleration of the vehicle S indicates deceleration, for example, when the airflow level of the air conditioner 20 is greater than the threshold level. The threshold level is the maximum value of the levels corresponding to the appropriate airflow level at the temperature state of the internal air temperature in which the restricted mode can be executed, and is, for example, level 1 shown in Figure 6. The threshold level is determined by experiment or simulation and stored in the memory unit 31.

[0103] Specifically, the air conditioning control unit 322 determines that, during the time from time Te to time Tf shown in Figure 6, the amount of accelerator pedal depression is less than or equal to the threshold depression amount (zero), and the vehicle speed has decreased from V11 to V12, thus indicating that engine braking is acting on the vehicle S. Even if the air conditioning control unit 322 determines that engine braking is acting on the vehicle S, it maintains the airflow level of the air conditioner 20 at level 2, which is higher than the threshold level.

[0104] In addition, the air conditioning control unit 322 may determine the airflow level of the air conditioner 20 based on whether or not the vehicle S is accelerating. For example, if the acceleration of the vehicle S is greater than or equal to a threshold acceleration, the air conditioning control unit 322 maintains the airflow level of the air conditioner 20. The threshold acceleration is, for example, an acceleration greater than zero and is stored in the memory unit 31. Specifically, the air conditioning control unit 322 maintains airflow level 2 of the air conditioner 20 because it has determined that the acceleration of the vehicle S is greater than or equal to a threshold acceleration during the time from time Tc to time Td shown in Figure 6. By operating in this manner, the air conditioning control unit 322 can suppress the output of the air conditioner 20 when the vehicle S is accelerating.

[0105] The air conditioning control unit 322 controls the output of the compressor 21 included in the air conditioner 20. The air conditioning control unit 322 controls whether or not to transmit power from the engine 10 to the compressor 21 by, for example, engaging or disengaging the clutch 25. For example, by engaging the clutch 25, the air conditioning control unit 322 transmits power from the engine 10 to the compressor 21, and by disengaging the clutch 25, it cuts off the power from the engine 10 that is transmitted to the compressor 21.

[0106] The air conditioning control unit 322 reduces the output of the compressor 21 when the vehicle S is accelerating to less than the output of the compressor 21 when engine braking is applied to the vehicle S. For example, if the air conditioning control unit 322 determines that engine braking is applied to the vehicle S, it engages the clutch 25 provided between the engine 10, which is the drive source of the vehicle S, and the compressor 21 included in the air conditioner 20. On the other hand, if the air conditioning control unit 322 determines that the vehicle S is accelerating, for example, if the acceleration based on the vehicle speed of the vehicle S is greater than or equal to a threshold acceleration, it disengages the clutch 25 connecting the engine 10 and the compressor 21.

[0107] As described above, the air conditioning control unit 322 can shut off the power from the engine 10 to the compressor 21 when the vehicle S is accelerating, making it easier to accelerate the vehicle S using the power of the engine 10. On the other hand, when engine braking is applied to the vehicle S, the air conditioning control unit 322 can transmit the power from the engine 10 due to engine braking to the compressor 21, allowing the compressor 21 to be operated with power not used for the vehicle S's movement. As a result, the air conditioning control unit 322 can reduce the interior air temperature while suppressing the power loss of the engine 10 when engine braking is applied to the vehicle S.

[0108] The air conditioning control unit 322 may determine a disconnection time, which is the time for disengaging the clutch 25 when the vehicle S is accelerating, and may disengage the clutch 25 during this disconnection time. The air conditioning control unit 322 determines the disconnection time to be a first time or a second time that is longer than the first time, based, for example, on the airflow level set for the air conditioner 20, a limit setting indicating whether or not a limit mode has been set, and whether or not the interior air temperature is such that the limit mode can be executed. For example, if the first time is 3 seconds, the second time is 9 seconds.

[0109] For example, if the acquisition unit 321 acquires a restriction setting indicating that no restriction mode is set, the air conditioning control unit 322 determines the disconnection time to be the first time. Specifically, during the time from time Tk to time Tl shown in Figure 6, the air conditioning control unit 322 determines that the vehicle S is accelerating because it has identified that the acceleration of the vehicle S, based on the vehicle speed acquired by the acquisition unit 321, is greater than or equal to the threshold acceleration. Then, the air conditioning control unit 322 determines the disconnection time to be the first time E1 because the acquisition unit 321 has acquired a restriction setting indicating that no restriction mode is set (the restriction setting shown in Figure 6 is OFF). By operating in this manner, the air conditioning control unit 322 can shorten the disconnection time of the clutch 25 when the airflow is not restricted, making it easier to lower the interior air temperature.

[0110] For example, when the limit setting acquisition unit 321 acquires a limit setting indicating that a limit mode has been set, the air conditioning control unit 322 determines whether the indoor air temperature is such that the limit mode can be executed. For example, during the period when the indoor air temperature changes from a first temperature to a second temperature lower than the first temperature, the air conditioning control unit 322 determines that the indoor air temperature is such that the limit mode cannot be executed. The first temperature is a preset temperature higher than the temperature at which occupants feel comfortable, for example, 35°C. The second temperature is a preset maximum temperature at which occupants feel comfortable, for example, 30°C. The first and second temperatures are stored in the storage unit 31.

[0111] For example, the air conditioning control unit 322 determines that the limit mode cannot be executed during the period when the indoor air temperature changes from 35°C to 30°C (the temperature state shown in Figure 6 is state CD). The air conditioning control unit 322 may also determine that the indoor air temperature is at a temperature where the limit mode cannot be executed during the period when the indoor air temperature changes from a temperature of 1 or higher to a 2nd temperature lower than the 1st temperature.

[0112] On the other hand, the air conditioning control unit 322 determines that the indoor air temperature is at a temperature at which the limit mode can be executed during periods other than the period during which the indoor air temperature changes from the first temperature to the second temperature. For example, the air conditioning control unit 322 determines that the state is such that the limit mode can be executed (the temperature state shown in Figure 6 is the NCD state) during periods other than the period during which the indoor air temperature changes from 35°C to 30°C. The air conditioning control unit 322 may also determine that the indoor air temperature is at a temperature at which the limit mode can be executed during periods other than the period during which the indoor air temperature changes from a temperature of first temperature or higher to a second temperature lower than the first temperature.

[0113] Then, the air conditioning control unit 322 determines the clutch 25 disengagement time to the first time if, for example, the limit setting acquisition unit 321 acquires a limit setting indicating that a limit mode has been set, and the air conditioning control unit 322 determines that the internal air temperature is such that the limit mode cannot be executed. Specifically, during the time from time Ta to time Tb shown in Figure 6, the air conditioning control unit 322 determines the disengagement time to the first time E1 because the limit setting indicates that a limit mode has been set (the limit setting shown in Figure 6 is ON), and the temperature condition is such that the limit mode cannot be executed (the temperature condition shown in Figure 6 is state CD).

[0114] By operating in this manner, the air conditioning control unit 322 can shorten the clutch disengagement time when the interior temperature is uncomfortable for the occupants (i.e., when there is a high need to lower the interior temperature), thereby increasing the operating time of the compressor 21. As a result, the air conditioning control unit 322 can more easily lower the temperature inside the vehicle S when the interior temperature is uncomfortable for the occupants.

[0115] The air conditioning control unit 322 identifies the airflow level it has set for the air conditioner 20, for example, when the acquisition unit 321 has acquired a limit setting indicating that a limit mode has been set, and the air conditioning control unit 322 has determined that the indoor air temperature is such that the limit mode can be executed. Furthermore, if the air conditioning control unit 322 determines the clutch disengagement time for the clutch 25 to be the second time, the air conditioning control unit 322 identifies the airflow level it has set for the air conditioner 20, for example, when the acquisition unit 321 has acquired a limit setting indicating that a limit mode has been set, and the air conditioning control unit 322 has determined that the indoor air temperature is such that the limit mode can be executed.

[0116] Specifically, during the time period from time Tg to time Th shown in Figure 6, the air conditioning control unit 322 determines that the limit mode is set to ON (the limit setting shown in Figure 6) and that the temperature condition is such that the limit mode can be executed (the temperature condition shown in Figure 6 is the NCD state). Furthermore, because the air conditioning control unit 322 determines that the airflow stage set for the air conditioner 20 is stage 1, it sets the clutch disengagement time to the second time E2, which is longer than the first time E1. By operating in this way, the air conditioning control unit 322 can lengthen the clutch disengagement time of the clutch 25 when there is little need to lower the interior air temperature. As a result, when the vehicle S is accelerating, the time it takes to transmit power from the engine 10 to the compressor 21 can be shortened, making it easier to accelerate the vehicle S.

[0117] The air conditioning control unit 322 identifies, for example, that the limit setting acquisition unit 321 has acquired an indication that a limit mode has been set, and that the air conditioning control unit 322 has determined that the indoor air temperature is such that the limit mode can be executed. Furthermore, if the air volume stage set on the air conditioner 20 is greater than the threshold stage, the air conditioning control unit 322 determines the clutch 25 disengagement time to the first time. Specifically, during the time from time Tc to time Td shown in Figure 6, the air conditioning control unit identifies that the limit setting is such that a limit mode has been set (the limit setting shown in Figure 6 is ON), and that the temperature state is such that the limit mode can be executed (the temperature state shown in Figure 6 is the NCD state). Furthermore, because the air volume stage set on the air conditioner 20 is stage 2, the air conditioning control unit 322 determines the clutch 25 disengagement time to the first time E1.

[0118] [Processing sequence of the air conditioning control device 30 in the second embodiment] Figure 7 shows an example of a processing sequence of the air conditioning control device 30 according to the second embodiment. The processing sequence shown in Figure 7 is a processing sequence for determining the disengagement time, which is the time for the air conditioning control device 30 to disengage the clutch 25. The air conditioning control device 30 executes the processing sequence shown in Figure 7 each time the vehicle S changes from a state other than an accelerating state to an accelerating state.

[0119] The acquisition unit 321 acquires a restriction setting from the operation unit 18 indicating whether or not a restriction mode has been set (step S51). If the acquisition unit 321 acquires a restriction setting indicating that a restriction mode has not been set (NO in step S52), the air conditioning control unit 322 determines the clutch disengagement time to the first time E1 (step S53). On the other hand, if the acquisition unit 321 acquires a restriction setting indicating that a restriction mode has been set (YES in step S52), the acquisition unit 321 acquires the indoor air temperature detected by the room temperature sensor 17 (step S54).

[0120] The air conditioning control unit 322 determines whether or not the limit mode can be executed based on the indoor air temperature acquired by the acquisition unit 321 (step S55). If the air conditioning control unit 322 determines that the control mode cannot be executed (NO in step S56), it sets the clutch 25 disengagement time to the first time E1 (step S53). If the air conditioning control unit 322 determines that the control mode can be executed (YES in step S56), it identifies the airflow level set for the air conditioner 20 (step S57).

[0121] If the specified airflow level is greater than the threshold level (NO in step S58), the air conditioning control unit 322 determines the clutch disengagement time to be the first time E1 (step S53). If the specified airflow level is less than or equal to the threshold level (YES in step S58), the air conditioning control unit 322 determines the clutch disengagement time to be the second time E2 (step S59).

[0122] [Effects of the air conditioning control device 30 according to the second embodiment] As described above, the air conditioning control device 30 according to the second embodiment has an air conditioning control unit 322 that controls the output of a compressor 21 included in the air conditioner 20 that conditioned the air inside the vehicle S. The air conditioning control unit 322 disengages the clutch 25 connecting the engine 10 and the compressor 21 when the acceleration based on the vehicle speed of the vehicle S is equal to or greater than a threshold acceleration. As a result, the air conditioning control unit 322 makes the output of the compressor 21 when the vehicle S is accelerating less than the output of the compressor 21 when engine braking is applied to the vehicle S.

[0123] With the air conditioning control device 30 configured in this way, the air conditioning control device 30 can shut off the power from the engine 10 transmitted to the compressor 21 when the vehicle S is accelerating, thereby making it easier to accelerate the vehicle S.

[0124] Furthermore, if the amount of accelerator pedal depression acquired by the acquisition unit 321 is less than or equal to a threshold depression amount, and the acceleration of the vehicle S is an acceleration indicating deceleration of the vehicle S, the air conditioning control unit 322 increases the airflow level of the air conditioner 20 while the clutch 25 is engaged. With the air conditioning control device 30 configured in this way, the airflow of the air conditioner 20 can be increased while power is being transmitted from the engine 10 to the compressor 21, even when engine braking is being applied to the vehicle S.

[0125] As a result, the air conditioning control device 30 can suppress the loss of output from the engine 10 when engine braking is applied to the vehicle S. Furthermore, even if the interior temperature rises when the clutch 25 is disengaged while the vehicle S is accelerating, the air conditioning control device 30 can pre-lower the interior temperature to maintain an interior temperature that the occupants find comfortable.

[0126] <Third Embodiment> In the third embodiment, an example will be described in which, while the vehicle S is accelerating, the air conditioning control device 30 decides whether or not to disengage the clutch 25 based on the interior temperature, which is the temperature inside the vehicle S, and a preset reference temperature inside the vehicle. The configuration of the vehicle S according to the third embodiment is the same as the configuration of the vehicle S according to the second embodiment, as shown in Figure 5.

[0127] The acquisition unit 321 acquires the vehicle speed of the vehicle S detected by the vehicle speed sensor 13 via the control device 11. The acquisition unit 321 also acquires the interior air temperature, which is the temperature inside the vehicle S, detected by the room temperature sensor 17. The acquisition unit 321 acquires the vehicle speed and interior air temperature of the vehicle S at regular intervals, for example.

[0128] The air conditioning control unit 322 determines the acceleration of the vehicle S based on the vehicle speeds of multiple vehicles S at multiple time points, which are acquired by the acquisition unit 321. If the acceleration based on the vehicle speed of the vehicle S is greater than or equal to a threshold acceleration, the air conditioning control unit 322 disengages the clutch 25 until the interior air temperature reaches a predetermined reference temperature. The threshold acceleration is, for example, an acceleration greater than zero, and is stored in the storage unit 31. The reference temperature is, for example, the maximum interior air temperature at which the occupants of the vehicle S feel comfortable, which is set by experiment or simulation, and is stored in the storage unit 31.

[0129] The air conditioning control unit 322 determines, for example, that the vehicle S is accelerating if its acceleration is greater than or equal to a threshold acceleration. Based on this determination, the air conditioning control unit 322 disengages the clutch 25. Subsequently, after disengaging the clutch 25, the air conditioning control unit 322 calculates a subtracted value by subtracting the internal air temperature acquired by the acquisition unit 321 from the reference temperature stored in the memory unit 31 at a predetermined cycle. The predetermined cycle is determined by experiment or simulation, and is, for example, 1 second. The air conditioning control unit 322 then re-engages the clutch 25, for example, when the sign of the calculated subtracted value changes.

[0130] [Effects of the air conditioning control device 30 according to the third embodiment] As described above, the air conditioning control device 30 according to the third embodiment has an air conditioning control unit 322 that disengages the clutch 25 until the interior air temperature reaches a predetermined reference temperature when the acceleration of the vehicle S is equal to or greater than a threshold acceleration. With the air conditioning control unit 322 configured in this way, the air conditioning control unit 322 can disengage the clutch 25 until the interior air temperature reaches a reference temperature when the vehicle S is accelerating. As a result, the air conditioning control unit 322 can maximize the time the clutch 25 is disengaged, while maintaining an interior air temperature that the occupants of the vehicle S find comfortable, compared to determining a first or second time as in the second embodiment.

[0131] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of its gist. For example, all or part of the apparatus can be configured by functionally or physically distributing and integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combinations are combined with the effects of the original embodiments. [Explanation of Symbols]

[0132] 10 Engines 11 Control device 12 Pedal Sensors 13. Vehicle speed sensor 14. Accelerometer 15 Tilt Angle Sensor 16. Outdoor temperature sensor 17 Room temperature sensor 18 Control section 20 Air conditioner 21 Compressor 22 Fans 23 Evaporator 24 motors 25 Clutch 26 Air outlet 30 Air conditioning control device 31 Storage section 32 Control Unit 321 Acquisition Department 322 Air Conditioning Control Unit 323 Decision Section

Claims

1. It has an air conditioning control unit that controls the output of a compressor included in the air conditioning system that provides air conditioning inside the vehicle's cabin, The air conditioning control unit reduces the output of the compressor when the vehicle is accelerating to a lower value than the output of the compressor when the engine brake is applied to the vehicle. Air conditioning control device.

2. An acquisition unit that acquires the set temperature of the air conditioning system set by the occupant of the vehicle, the cabin temperature of the vehicle's passenger compartment, the amount the accelerator pedal of the vehicle is pressed, and status information indicating that the vehicle is in motion. A determination unit that determines the target temperature of the vehicle interior based on the set temperature and the amount of foot depression, It further possesses, The air conditioning control unit controls the output of the compressor of the air conditioning system based on the subtracted value obtained by subtracting the target temperature from the cabin temperature. The determination unit determines a target temperature lower than the set temperature based on the state of the vehicle included in the state information, when the amount of foot pressure changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount. The air conditioning control device according to claim 1.

3. The determination unit determines the target temperature based on the state information, which includes at least one of the following: the vehicle speed, the vehicle acceleration, the vehicle deceleration, the ambient temperature of the vehicle, and the gradient of the road surface on which the vehicle is traveling. The air conditioning control device according to claim 2.

4. The determination unit lowers the target temperature as the vehicle speed decreases at the timing when the amount of pedal depression changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount. The air conditioning control device according to claim 3.

5. The determination unit lowers the target temperature as the ambient temperature is higher at the moment when the amount of footing changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount. The air conditioning control device according to claim 3.

6. The determination unit lowers the target temperature as the deceleration increases after the amount of footing changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount. The air conditioning control device according to claim 3.

7. The determination unit, if the condition in which the road surface gradient remains downward after the amount of footing changes from an amount greater than a predetermined amount to an amount less than or equal to the predetermined amount continues for a predetermined time, changes the target temperature, which has been determined to be lower than the set temperature, to the set temperature. The air conditioning control device according to claim 3.

8. The determination unit changes the target temperature, which was determined to be lower than the set temperature, to the set temperature when the amount of foot pressure changes from an amount greater than the predetermined amount to an amount less than or equal to the predetermined amount and the vehicle stops, and further changes the target temperature to a higher temperature than the set temperature when the vehicle starts moving after stopping. The air conditioning control device according to claim 3.

9. The determination unit determines that, if the vehicle starts moving after coming to a stop, the lower the vehicle speed after starting, the higher the target temperature. The air conditioning control device according to claim 8.

10. The determination unit, when the vehicle starts after stopping, raises the target temperature as the acceleration after departure increases. The air conditioning control device according to claim 8.

11. The determination unit, if the vehicle has stopped and then departs, and if the road surface gradient after departure remains uphill for a predetermined period of time, changes the target temperature, which has been determined to be higher than the set temperature, to the set temperature. The air conditioning control device according to claim 8.

12. The system further includes an acquisition unit that acquires the vehicle speed of the aforementioned vehicle. The air conditioning control unit disengages the clutch connecting the vehicle's drive source and the compressor when the acceleration based on the vehicle's speed is greater than or equal to a threshold acceleration. The air conditioning control device according to claim 1.

13. The air conditioning control unit determines the disengagement time, which is the time for disengaging the clutch, to be a first time or a second time that is longer than the first time, based on the airflow levels of the air conditioning unit, which can set the airflow in multiple stages; a restriction setting indicating whether or not a restriction mode is set in which air is blown out at an airflow level lower than the airflow level corresponding to the target value of the temperature of the air blown out from the outlet of the air conditioning unit; and whether or not the interior air temperature, which is the temperature inside the vehicle, is at a temperature in which the restriction mode can be executed. The air conditioning control device according to claim 12.

14. When the air conditioning control unit obtains the restriction setting indicating that the restriction mode is not set, the unit determines the disconnection time to the first time. The air conditioning control device according to claim 13.

15. The air conditioning control unit determines that during the period when the internal air temperature changes from a first temperature to a second temperature lower than the first temperature, the internal air temperature is at a temperature at which the restriction mode cannot be executed, and during other periods different from the aforementioned period, the internal air temperature is at a temperature at which the restriction mode can be executed. The air conditioning control device according to claim 13.

16. The air conditioning control unit determines the cutoff time to the first time if the acquisition unit acquires the restriction setting indicating that the restriction mode has been set, and the air conditioning control unit determines that the indoor air temperature is at a temperature at which the restriction mode cannot be executed. The air conditioning control device according to claim 15.

17. The air conditioning control unit determines the cutoff time to the second time if the acquisition unit acquires the limit setting indicating that the limit mode has been set, the indoor air temperature is at a temperature at which the limit mode can be executed, and the airflow level set in the air conditioning device is below the threshold level. The air conditioning control device according to claim 15.

18. The acquisition unit further acquires the amount the accelerator pedal of the vehicle is pressed, The air conditioning control unit increases the airflow level when the amount of foot pressure is less than or equal to a threshold amount of foot pressure and the acceleration is an acceleration indicating deceleration of the vehicle. The air conditioning control device according to claim 13.

19. The air conditioning control unit maintains the airflow level even if the step amount is less than or equal to the threshold step amount and the acceleration is an acceleration indicating deceleration of the vehicle, when the airflow level is greater than the threshold level. The air conditioning control device according to claim 18.

20. The air conditioning control unit maintains the airflow level when the acceleration is equal to or greater than the threshold acceleration. The air conditioning control device according to claim 13.

21. The acquisition unit further acquires the interior air temperature, which is the temperature inside the vehicle's cabin. The air conditioning control unit disengages the clutch when the acceleration based on the vehicle speed is greater than or equal to a threshold acceleration, until the internal air temperature reaches a predetermined reference temperature. The air conditioning control device according to claim 12.

22. The processor executes The air conditioning system includes an air conditioning control step that reduces the output of the compressor, which is included in the air conditioning system that provides air conditioning in the vehicle's cabin, to a lower level when the vehicle is accelerating than when the engine brake is applied to the vehicle. Air conditioning control method.

23. In the processor, An air conditioning control process is performed to reduce the output of the compressor included in the air conditioning system that provides air conditioning in the vehicle's cabin to a lower value when the vehicle is accelerating than when engine braking is applied to the vehicle. A program to be executed.

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